Category: White Paper

Pneumatics vs Hydraulics

With the advent of the Covid 19 pandemic, there has been an acceleration toward automation. Packaging solutions and advances have also become important. Pneumatics plays a very large part in both automation and packaging as outlined below in the blog

Part of pneumatic technology is the use of compressed air for blowing, moving and cooling. The rugged nature and general low cost of compressed air products for these applications as well as the extremely low level of maintenance required have become more important criteria where downtime and maintenance costs have also risen dramatically especially when compared to more complex and expensive capital cost alternatives.

Pneumatic and hydraulic systems have many similarities. Both pneumatics and hydraulics are applications of fluid power. They each use a pump as an actuator, are controlled by valves, and use fluids to transmit mechanical energy. The biggest difference between the two types of systems is the medium used and applications. Pneumatics use an easily compressible gas such as air or other sorts of suitable pure gas—while hydraulics uses relatively incompressible liquid media such as hydraulic or mineral oil, ethylene glycol, water, or high temperature fire-resistant fluids. Neither type of system is more popular than the other because their applications are specialized. This article will help you make a better choice for your application by describing the two types of systems, their applications, advantages, and disadvantages. The load or the force that you need to apply, the output speed, and energy costs determine the type of system you need for your application.

What is Pneumatics?

Pneumatics is a branch of engineering that makes use of pressurized gas or air to affect mechanical motion based on the working principles of fluid dynamics and pressure. The field of pneumatics has changed from small handheld devices to large machines that serve different functions. Pneumatic systems are commonly powered by compressed air or inert gases. The system consists of interconnected set of components including a gas compressor, transition lines, air tanks, hoses, standard cylinders, and gas (atmosphere). The compressed air is supplied by the compressor and transmitted through a series of hoses. The air flow is regulated by manual or automatic solenoid valves and the pneumatic cylinder transfers energy provided by the compressed gas to mechanical energy. A centrally located and electrically powered compressor powers cylinders, air motors, and other pneumatic devices. Pneumatic systems are controlled by a simple ON/OFF switch or valve.

Most industrial pneumatic applications use pressures of about 80 to 100 pounds per square inch (550 to 690 kPa). The compressed air is stored in receiver tanks before it is transmitted for use. The compressors ability to compress the gas is limited by the compression ratios.

Applications

Pneumatic systems are typically used in construction, robotics, food manufacturing and distribution, conveying of materials, medical applications (dentistry), pharmaceutical and biotech, mining, mills, in buildings, and tools in factories.  Pneumatic systems are primarily used for shock absorption applications because gas is compressible and allows the equipment to be less susceptible to shock damage.

Applications of pneumatic systems include:

• Air compressors
• Vacuum pumps
• Compressed-air engines and vehicles
• HVAC control systems
• Conveyor systems in pharmaceutical and food industries
• Pressure sensor, switch and pump
• Precision drills used by dentists
• Air brakes used by buses, trucks, and trains
• Tampers used to pack down dirt and gravel
• Nail guns
• High pressure bank’s drive-teller tubes
• Manufacturing and assembly lines
• Pneumatic motor, tire, and tools

Advantages and Disadvantages of Pneumatics

Pneumatic systems are selected above hydraulic systems because of the lower cost, flexibility, and higher safety levels of the system. Pneumatic systems are best suited for applications which require no risk of contamination because they offer a very clean environment for such industries as biotech, dentistry, pharmaceutical, and food suppliers.  Since they use clean, dry, compressed air, the system can quickly convey items. The straight and simple design prevents clogging and reduces maintenance. Pneumatic systems are easy to install and portable. They are reliable and has an initial low setup cost because they operate on comparatively low pressure and inexpensive components that reduces operation costs.

No container is required to store the air that will be compressed because it is drawn from the surrounding atmosphere and filtered (optional). The entire system is designed using standard cylinders and other components. The air or gas used in a pneumatic system is typically dried and free of moisture so that it does not create issues to internal components.

Pneumatic systems provide rapid movement of cylinders because the air compressor flow rates. Air is very agile and can flow through pipes very easily and quickly with little resistance. Pneumatic systems are available in a wide variety in very small sizes.  The pneumatic systems are clean and do not pollute because any exhaust is released into the atmosphere. The Pneumatic system is more agile because if the system needs to change directions, the simple design and control allows operators to update the system quickly without environmental impact.

Pneumatics are cheaper than hydraulic systems because air is inexpensive, plentiful, easy to obtain, and store. Pneumatic systems generally have long operating lives and require little maintenance because gas is compressible, and the equipment is less subject to shock damage. Unlike hydraulic systems that use liquids that transfers force, gas absorbs excessive force.

Safety is an important advantage of choosing Pneumatic systems.  Since Pneumatic systems run on compressed air, there is very little chance of fire compared with explosion or fire hazard of using compressed hydraulic oil. It is also maintenance free since there is little need to replace filters.

It is essential to determine the amount of force required for your application because not as much force is created with pneumatic systems as with hydraulic systems. Pneumatic systems do not offer the same potential force as hydraulic systems so they should not be used for applications that require lifting or moving heavy loads.  Compressed air experiences air pressure fluctuations, so that movement can be jerky or spongy at times while moving or lifting loads. A larger cylinder is needed to produce the same force that a hydraulic ram can produce. In terms of energy costs, pneumatic systems cost more than hydraulics because the amount of energy lost through heat produced while compressing air. Another significant concern about pneumatic systems is the noise that is created. If used, it is the responsibility of the owners to protect their workers from hearing loss.

What is Hydraulics?

Hydraulics is used for the generation, control, and transmission of power using pressurized liquids. It is a technology and applied science involving mechanical properties and use of liquids. Hydraulic systems require a pump and, like pneumatic systems, uses valves to control the force and velocity of the actuators. Industrial applications of hydraulics use 1 000 to 5 000 psi or more than 10 000 psi for specialized application. The word hydraulics originates from Greek words hydor – water and aulos – pipe. The following equipment is required for a hydraulic system: hydraulic fluid, cylinder, piston, pumps, and valves that control the direction of flow, which is always in one direction.

Hydraulic systems, unlike Pneumatic systems are often large and complex.  The system requires more room because a container is required to hold fluid that flows through the system.  Since the size of the system is larger, it requires more pressure; making it more expensive than Pneumatic systems. Due to their overall larger size and the incompressibility of oil, hydraulic systems can lift and move larger materials.   Hydraulic systems are slower because oil is viscous and requires more energy to move through pipes. During configuration and planning, if the factory or plant has several hydraulic machines, it is ideal to have a central power unit to reduce noise levels.

Applications

Due to the risk of potential hydraulic oil leaks from faulty valves, seals or hoses – hydraulic applications do not apply to anything that would be ingested – such as food and medical applications. They are used in a variety of everyday machine applications:

• Elevators
• Dams
• Machine tools: hydraulic presses, hoppers, cylinders, and rams
• Amusement parks
• Turbines
• Dump truck lift
• Wheelchair lift
• Excavating arms for diggers
• Hydraulic presses for forging metal parts
• Wing flaps on aircraft
• Hydraulic braking system in cars
• Lift cars using a hydraulic lift
• Jaws of life

Advantages of Hydraulics

Hydraulic systems are more capable of moving heavier loads and providing higher forces due to the incompressibility of liquids. Hydraulic systems do many purposes at one time, including lubrication, cooling, and power transmission. Hydraulic powered machines operate at higher pressures (1 500 to 2 500 psi), generating higher force from small-scale actuators. To effectively use a hydraulic system, it is essential to pick an appropriately sized component to match the flow.

Hydraulic systems are larger and more complicated systems.  Liquid, such as hydraulic oil is viscous and requires more energy to move. A tank is also required to store the oil from which the system can draw from when the oil is reduced.  The initial costs are higher than Pneumatic systems because it requires power that needs to be incorporated into the machine.

Any leaks in a hydraulic system can cause serious problems. This system cannot be used for food applications due to high risk of hydraulic oil leaks from faulty seals, valves, or burst hoses.  Appropriate plumbing procedures, preventative and regular maintenance, and having the correct materials on hand to minimize potential leaks and to quickly remedy any issues need to be in place at each site. In conclusion, pneumatic devices are best suited to execute low scale engineering and mechanical tasks while hydraulic systems are best for applications that require higher force and heavy lifting.

Summary:
In general, it is a good rule of thumb to use hydraulic systems primarily for heavy lifting applications such as the jaws of life, elevators, hydraulic presses and arms in heavy equipment, and wing flaps for airplanes because these types of systems operate at higher pressures (1 500 to 2 500 psi), generating higher force from small-scale actuators. When it comes to moving or manufacturing products, especially food or pharmaceutical, it is recommended to use pneumatic systems because there is no chance of contamination due to burst pipes or oil leaks. Nex Flow Air Products Corporation manufactures compressed air products for blow off, industrial cooling (Vortex Tubes), air operated conveying, and air optimization designed to reduce energy costs while improving safety and increasing productivity in your factory and manufacturing environments.

Engineered air jets, air knives, air amplifiers, and air nozzles are examples of blow off products manufactured and sold by Nex Flow. They are safe because they meet OSHA noise and pressure requirements. Air Amplifiers are recommended for purging tanks, venting fumes, smoke, lightweight materials from automobiles, truck repair, or from other confined spaces. These products are also used to clean and dry parts, remove chips, and part ejection. They can also be used as effective tools for your manufacturing environment.

Vortex tube industrial cooling applications converts compressed air into very cold air for spot cooling.  Nex Flow provides Vortex Tubes and Cabinet Enclosure Coolers. These products are ideal for use in high temperature and harsh environments. These products are especially ideal for use in high temperature and harsh environments. They also provide smaller vortex tube operated mini-coolers and vortex cooling for tool cooling systems. These systems can provide extremely cold temperatures without the use of refrigerants, such as CFCs or HCFCs.  Industrial vortex tube powered cooling products are recommended for cooling gas samples, heat seals, data centers, electronic and electrical control instruments and environmental chambers.

Compressed air operated pneumatic conveyors are designed to move materials at high rates and over long distances. They are ideal for continuous or intermittent use since they are operated by an on/off switch and controlled by a regulator.  Our air operated conveyors are compact and have no moving parts. Nex Flow also provides fume and dust extractors, Ring Vac Operated conveyors and an X-StreamTM Hand Vac system. Air operated pneumatic conveyors are primarily used for conveying materials for applications where vacuum force is required to move objects over long distances at high speeds. These devices have an on/off switch to enhance safety. It uses compressed air, not electricity, so there is no explosion hazard. The Nex Flow Ring Vacs are made of anodized aluminum or stainless steel. They are designed to transport or vent a wide variety of lightweight products, raw materials, or fumes from one place to another in your factory. For high temperature and corrosive applications, regular and high temperature stainless steel is available. When moving food and pharmaceutical products, 316L Stainless Steel pneumatic conveyors are used. The specially design non-clogging model XSPC air operated conveyors are easy to install and use, compact and portable, and maintenance free.

The systems offered by Nex Flow optimize compressed air system operations because of efficient design.  The systems can be easily turned on and off so that the compressed air is used only when needed. The products do not have high maintenance costs and are light weight. System optimization can be achieved with the compact sound meter, ultrasonic leak detector and PLC flow control (PLCFC) system for compressed air, which uses photoelectric sensors to turn on the air when the target passes the sensor and to turn off the air when it leaves the sensor or can be set by time. This device can be used for dust and debris blow-off, part drying system, cooling hot parts, and cleaning parts before packaging. Nex Flow offers various accessories that are integrated into pneumatics systems to increase the efficiency of compressed air conveying products and systems. Some accessories include nozzles, mufflers, filters, mounting systems and static control for blow off of dust and debris from statically charged surfaces.

Nex Flow pneumatic products reduce noise, enhance factory safety, and provide excellent venting, cooling, and blow-off solutions. Compressed air conveying systems provides instant response times and are the most efficient and effective way to convert pressure into useful flow.  The cost-effective pneumatic conveying systems provided by Nex Flow are simple, light weight, compact, reliable, and easy to install and use. Since there are no moving parts, pockets or angles to collect debris, moisture, or water, the maintenance costs are minimal. Expect the best from Nex Flow technicians, who are trained to help you determine the best solution for your application.

This article not only touches on how to calculate the cost of compressed air based on electricity cost alone but also the actual cost once heat recovery is integrated. If you would like to calculate compressed air cost based on electricity alone please refer to the below compressed air cost calculator and example.

Most industrial facilities use compressed air, whether it’s for running air tools, pneumatic controls for conveying, cooling and blow off. A survey by the U.S. Department of Energy (DOE) shows that for a typical industrial facility, approximately 10% of the electricity consumed goes to generating compressed air. This is a significant amount – therefore knowing the cost of this compressed air is important.

For some manufacturing facilities, the cost of compressed air generation may account for 30% or more of the electricity consumed in the plant. Some companies use a value of 30 cents to 50 cents per 1,000 cubic feet of air as an estimate but in reality actual cost can vary greatly. Air compressors are considered notoriously inefficient when looked at as a separate entity. However, the real cost should also take into consideration the recovery of waste heat generated by the heat of compression. The heat of compression is the heat generated when air is compressed. It is removed using intercoolers between compressions stages and again using an aftercooler at the end of the compression cycles.

If this waste heat is used for the production process, or to heat the premises, it is possible to achieve impressive efficiencies of well over 90 percent. In fact, of the 100 percent of the electrical energy consumed, some 94 percent is converted to heat, that can be put to good use after it has been recovered. This does not actually make compressed air cheaper per cubic meter to produce, but there are significant savings when this waste heat is used for other purposes such heating buildings or water.

The lifetime cost of compressed air excluding heat recovery consists of:

1. Equipment and Installation Cost – about 12%
2. Maintenance Cost – about 12%
3. Electricity Cost – about 76% 

However, the cost of compressed air is usually taken as only the electrical cost. Considering that alone (and not the other costs and not the recovered cost from using waste heat), provides the usual daily usage cost of compressed air. The overall efficiency of a typical compressed air system can be as low as 10% to 15%. For example, to operate a 1-hp air motor at 100 psig, approximately 7 to 8 hp of electrical power is supplied to the air compressor.

To calculate the cost of compressed air based on electrical cost alone, use the following formula:

Variables:

• hpb = compressor shaft horsepower (often higher than the motor nameplate horsepower and can be checked under the equipment specification)
• Percent time = percentage of time running at this operating level,
• Percent full-load hpb = hpb as percentage of full-load hpb at this operating level, and
• Motor efficiency = Efficiency of the electric motor at this operating level.

Calculation Example

A typical manufacturing facility has a 100 hp compressor (which requires 110 hpb) that operates for 7,000 hr annually. It is fully loaded 85% of the time (motor efficiency is 95%) and unloaded the rest of the time (25% full-load hpb and motor efficiency is 90%). The aggregate electric rate is $0.10/kWhr.

1. Calculate the cost when fully loaded:
   ((110 hp) X (0.746) X (7,000 hr) X ($0.10/kw-hr) X (0.85) X (1.0))/.95 = $51.396.00
2. Calculate the cost when partially loaded:
   ((110 hp) X (0.746) X (7,000 hr) X ($0.10/kw-hr)X (0.15) X (0.25))/.90 = $2393.00
3. Annual energy cost = $51,396.00 + $2393.00 = $53,789.00

Note: The general rule to approximate performance of a compressor is about 4 to 4.5 SCFM/Hp. So using an average of 4.25 SCFM/HP a 100 HP compressor will produce 425 SCFM.

For 7000 hours of operation the cost per 1000 cubic feet in this case would be:

$53,789/(425 SCFM X 7000 hr. X 60 Minutes/hr.) X 1000 cubic feet) = $0.30 / 1000 cubic feet.

But…. what if there is heat recovery?

Can Compressors Actually be Energy Savers?

Chemical and food processing operations use temperature controlled processes and have a year-round requirement for heat.  

Paint shops and electroplating operations also need a constant supply of heat for their processes. In plants that do not require process heat, the user has the choice between either heating the premises or heating water.

Modern water-cooled compressors are easily integrated into a heat recovery system. There are a lot of much older compressor stations, though, that work without heat recovery. For stations such as these, there are many systems on the market that can be purchased to utilize heat recovery. This turns the compressor into an “energy saver” with a surge in overall efficiency, no matter what the original model or output was.

The investment costs for a heat recovery systems depend largely on the structural conditions at the site but paybacks are usually under a year.

Air-cooled systems can use the exhaust air to heat rooms or production facilities. This can also be very easily achieved using the outdoor thermostat control. In this case, from a defined temperature upwards, the exhaust air stream from the sound insulation hood is switched over to heat the production facility when temperatures drop – and all this comes at no extra cost.

So what is the “real” cost of compressed air. If there is a heat recovery system. Let’s assume the heat recovery system saves even a small amount – say $10,000.00 a year. Then the $53,789.00 cost is really $43,789.00 because we can utilize the heat byproduct.

The cost per 1000 cubic feet reduces to: $0.245/1000 cubic feet which is quite dramatic.

Considering that compressed air operated equipment tends to be more rugged, simpler and that compressed air operated equipment compared to hydraulic or electrical equipment is safer, faster and more user friendly, the real cost of using compressed air is not just the electricity that runs the air compressor. You need to take into account many other factors such as heat recovery, and the maintenance costs and uses of the compressed air operated equipment itself.

Conclusion

In view of low investment, compressed air users should seriously consider the option of utilizing waste heat. Even a relatively small , 25 hp compressor provides enough waste heat to keep a domestic dwelling warm. It is also a good idea to look into the fine tuning of other factors involved in the efficiency of compressed air supply. These include recommendations on the pressure level, optimizing the regulation with as low a pressure range as possible, the use of variable speed compressors for peak loads, and reducing inefficient idle times. Regular leak testing, which can also be achieved electronically by modern control systems, through measuring the drop in pressure when the compressors are switched off, then using a leak detector to find leaks and fix them.

A Ring Vac is a compressed air operated conveyor that works on a Venturi principle.  Compressed air is input into the Ring Vac internal plenum chamber and exits from several holes drilled around the inside diameter of the unit in the direction of flow out of the unit creating a vacuum at the inlet end. The holes are designed to minimize compressed air use and optimize the creation of the vacuum.   The air flow outlet is amplified approximately 6 times that of the inlet compressed air. Unlike “coanda” profile air operated units called “air amplifiers” the air operated conveyor device create a much higher vacuum and less air flow amplification. For this reason they are excellent for conveying products longer distances.   A pipe or tube is connected to each end of the unit. Material is fed into one end and exits at the other. How far vertically and horizontally can the unit convey depends on the physical size of the unit (vacuum decreases as size increases) and the nature (weight, size and shape) of the material conveyed.   

As for products to be conveyed they may be small particles, powders, larger materials and even gasses.  Venting can be a great application for Ring Vacs especially if the gasses are not clean as will be explained further.

Because these units use compressed air, they are not likely to be used to conveying tons of material.  Instead, they are best suited for primarily intermittent applications (or continuous applications where low pressure is needed such as in gas venting) and for capacities limited to under 15 pounds or 7 kg per minute. Within these limits however, Ring Vacs can effectively and economically replace electrically operated vacuum pumps in all sorts of applications and industries. Now, let’s look at its compatibility with different types of materials.

Compatibility with solids:  When conveying solid materials, the material in size should be no more than 50% of the size of the inlet diameter of the Ring Vac to avoid getting stuck.   An exception is, for example if a long (but thin piece) that will fit through the unit is fed into the Ring Vac. In that case, as with other materials, it will be drawn in and accelerated to a high speed and conveyed along the pipe or tube to which it is connected.   Standard Ring vac units are available in anodized aluminum, a more powerful version in hard anodized aluminum to handle more abrasive materials, and in 303/304 stainless steel for corrosive and high temperature applications and in 316L stainless steel for higher corrosive environments and for food and pharmaceutical applications such as in the conveying of capsules and pills. Ring Vacs may be manufactured out of special materials for conveying materials if the standard materials are not compatible.

Conveying powder:  Moving powder is easy with a Ring Vac but it’s the powder “exiting the unit that has to be dealt with. The powder leaves at a high velocity and when the powder exits and is collected, a large dust cloud can be created.  So whatever container it enters must be deep enough to contain the cloud. Using a fine filter to contain the cloud will not work because the back pressure caused by too fine a filter will negatively affect the conveying performance.  In one creative application, a stainless steel Ring Vac was used to convey seasoning from one vat to another to be mixed with other material. The seasoning was fine powder. On the vat where the seasoning was conveyed, the customer installed a “chimney” that was tall enough to contain the cloud created when the material went into the vat. At the top of the chimney was a “coarse” filter which allowed for the air flow to exit but enough to contain the seasoning.

Small Particles:  With small particles and also with powder, when the material is collected at the inlet side of the Ring vac (we restate that you need to attach some pipe or tube at the inlet end as well as at the outlet to collect the material for best performance), the material needs to “breathe” to be drawn into to conveyor.  So placement of the inlet tube or pipe and design is important. But once inside the unit they are easy to convey.

Large Objects: The main thing to note in conveying larger materials is that the size or dimension of the object should not be greater than 50% of the inside diameter of the Ring Vac to avoid getting stuck. If the materials are smaller than half the inside diameter – even relatively heavy objects such as screws and nails can be conveyed effectively. 

Compatibility with Gas: Gas venting is one major application.  Air Amplifiers can also be used but there is one major advantage of using Ring Vacs and that is the intrinsic design.  When air amplifiers convey gas, if the gas is dirty, material can deposit onto the “coanda” profile and after some time negatively affect performance and even stop working when the buildup of dirt and debris becomes critical.   The design of the Ring Vac is such that the chance of dirt depositing over the air exit holes is greatly minimized. Also, when using the unit for venting applications you require very little air pressure to move the gasses, even as low as a few PSIG with some applications using only 1 PSIG if conveying a short distance.   It is with materials that one has to be careful in moving gasses. Some gasses may be highly corrosive, and sometimes you end up dealing with very high temperatures. For example, high temperature stainless steel units are used to vent hot sour gas and sometimes must handle up to 1200 oF. (649 oC).   Special ones made of Teflon have replaced vacuum pumps in scrubbers and use very low input pressure to operate, eliminated high maintenance costs associated with electrically operated vacuum pumps for the same application.   Special flanged versions with different materials have been made for many venting and gas conveying applications in a variety of manufacturing such as battery production.

Compatibility with Liquid: Ring Vacs have been used with limited success in liquid conveying and the smaller sizes may be used.  They are not really designed for liquid handling and not an application that is encouraged. However, for the smaller sizes (1” and smaller) and for limited distances, they have, and are being used.

Summary: Whether Ring vac are used for conveying solid material, large or small, or powders or for venting gasses, they are economical for smaller capacities outlined above and especially ideal for intermittent applications in the case of solids, or low pressure applications in the case of venting. Like nozzles, air knives or any other compressed air accessories they are virtually maintenance free with no moving parts.   They can be made out of a variety of materials, special sizes and shapes have been designed and manufactured for all types of industries – plastics industry for hopper loading, natural gas transmission for venting compressors, semiconductor industry for gas venting, food industry for conveying ingredients, etc.   In every case the more costly alternative was vacuum pumps. It would be good to check your operation as to where vacuum pumps are now used to evaluate whether a Ring vac can provide a lower cost, more efficient, alternative.

Industrial Panel Air Conditioning Options and Trends

The various options for cooling electrical cabinet coolers include, traditional compressor-based air conditioners, air-to-air heat exchangers (with heat pipes), thermoelectric air conditioners, and finally vortex coolers. Each cooling method has its plus’s and minus’s.

Sensitive electronic devices are used increasingly in hostile environments. High temperatures, contaminant-laden air, high humidity and corrosive atmospheres are bound to negatively affect sensitive electrical and electronic equipment. Damage to the controls can result in costly repairs, downtime, and even lost data. Inadequate protection of the controls can cause unwanted heat buildup, which can increase an enclosure’s internal temperature above the manufacturer’s recommended ratings for electronics/electrical equipment installed inside. This heat can come from both internal and external sources.

Internal heat sources come from the very components that needs cooling. These include:

• Variable Frequency Drives (VFD’s)/inverters
  
• Battery Pack back-up systems
  
• Communication equipment
  
• PLC systems
  
• Power supplies
  
• Routers & switches
  
• Servers
  
• Transformers

External heat sources come from the factory environment. Including:

• Heat from blast furnaces and foundries in heavy steel and metals production
  
• engine rooms
  
• food processing factories with high humidity and heat
  
• industrial ovens from bakeries and paint facilities
  
• hot climates in general
  
• manufacturing plants, especially producers of materials like insulation, carbon black or where other airborne dust and dirt particles are in the factory atmosphere
  
• outdoor solar heat gain if the control are in direct sunlight
  
• uninsulated and/or non-air conditioned buildings that heat up during the day

Although these heat sources may present a problem and potential damage to the systems – there are various methods in keeping the control panel cool. Here are some ways along with their advantages and drawbacks.

Traditional Compressor-Based Air Conditioners
Pros: High cooling capacity
Cons: Higher maintenance, high capital cost, more sensitive to breakdown the worse the environment

Compressor-Based air conditioners rely on chemical refrigerants to remove heat from electronic/electrical enclosures. In addition to refrigerants, these air conditioners also use compressors, evaporators, condensers, and fans to provide cooling.  The refrigerants used in the past are being replaced with more environmentally friendly products but the cost of these new refrigerants are sometimes ten times that of the obsolete refrigerants. In addition, some if not most of these new refrigerants are flammable which means there are design changes to insure safety when connected to a control panel with a potential to produce a “spark”. These units produce condensate which must be removed.  Fans need filters which must be cleaned or replaced. If mounted on equipment subject to vibration then the refrigerant can leak out prematurely and need costly replacement. This also means more shutdowns affecting production. Depending on the factory environment lifespan of a traditional air conditioner can be anywhere from five to ten years but in very harsh environments, much much less.

Air-to-Air Heat Exchangers
Pros: Low maintenance, relatively inexpensive
Cons: Cannot cool below ambient so limited by environment.

Efficient, cost-effective cooling can be realized through heat pipe assembly systems. These air-to-air heat exchangers remove waste heat from sealed electrical panels and enclosures to protect sensitive electronic components without exposing them to harsh, dirty environments outside the cabinet, a nice advantage.  Simple design means long life as well, although because they use fans, the fans need to have care and maintenance, especially in harsh factory environments. However, the big problem is that you cannot cool below the environment ambient temperature and in many factory environment that temperature is still too high and therefore limiting the use of this technology.  

Thermoelectric Air Conditioners
Pros: Reliable, relatively low maintenance
Cons: Cooling capacity is limited, and must be careful to size accurately, potentially use much more power to operate, extra care needed in installation.

Thermoelectric solid-state air conditioners utilizing the Peltier effect were introduced some years ago but only have limited use for a variety of reasons.  This effect is harnessed by using two elements of a semiconductor constructed from doped bismuth telluride. Upon application of a direct current (DC) power source, the device transfers heat from one side to the other. The side that heat is taken from becomes cold. They can dissipate loads up to 2,500 BTU/hr.  However, there are some issues to consider. Peltier modules release a large amount of heat in the course of operation. They require in the cooler heatsinks and fans capable of efficiently deflecting surplus heat from the cooling modules. Thermoelectric modules are noted for their relatively low efficiency coefficient; when they act as heat pumps, they are powerful sources of heat. Using these modules in cooling devices however, intended to protect the electronic components of the computer, dramatically increases the temperature within the system unit. This sometimes requires additional cooling devices within the controls. If you don’t use additional cooling, the high temperatures can complicate operating conditions — even for the modules. Also, using Peltier modules creates a relatively heavy extra load for the power supply to handle.  At the cooling side, the low temperatures produced by the operation of Peltier coolers can be too low and cause moisture from the air to condense inside the cabinet. This is dangerous for electric components. Therefore extra care needs to be taken in choosing the correct unit. When choosing a Peltier module of appropriate cooling power, it is necessary to ensure that the entire surface of its cold and hot sides are used. Otherwise, the parts of the module that do not have contact with the surface of the protected object (such as a processor chip) will only waste power and emit heat, decreasing overall cooling efficiency, possibly quite dramatically. One comment made by an informed user was that “They only become effective when the temperature differential is large enough. In most cases it will just increase the wattage drawn without doing anything that much better than a plain air conditioner.”   The cold side gets cold, but then you’ve got an even larger amount of heat to remove from the hot side. So you need an even larger heatsink or some heat removal system on the other side. Hence the extra care in any installation.

Vortex Coolers
Pros: Low maintenance, small footprint, low cost, keeps out moisture and dirt, no condensate, not subject to vibration, easy to install.
Cons: Require compressed air

Vortex coolers can be a low cost way to cool and purge electronic/electrical enclosures, especially in situations where conventional cooling by enclosure air conditioners is not possible. Applications may include small to medium size equipment enclosures.  Vortex coolers use compressed air to provide a cooling air flow. This means they are limited to applications where there is a ready source of clean, compressed air such as in medium to large industrial plants. The positive aspect is that it is these sizes of factories that usually have the cooling issues with their electrical and electronic control panels – hot and humid environment, and dirt and particulate in the atmosphere, have the compressed air. 

The primary component in a vortex cooler is a vortex tube, also known as the Ranque-Hilsch vortex tube that creates a swirling effect from the compressed air input and separates it into hot and cold air streams. A vortex cooler is unique in that it has no moving parts. At the end of the hot tube, a small portion of this air exits through a needle valve as hot air exhaust. The cold is pushed into the enclosure which air conditions the cabinet.  A properly designed vortex cooler like the Nex Flow panel Cooler has a built-in exhaust so there is no need to vent the enclosure, and has been tested and NEMA (and/or IP) approved to insure no water can get inside a cabinet from the outside. This vortex provides a positive purge on the cabinet, which also helps to keep dirt, dust and debris out of the enclosure.  There is no condensate to deal with. Because the compressed air is filtered to be clean and moisture removed (a necessary requirement with vortex coolers), even if the compressed air supply is saturated with moisture before the filter, there will be no moisture inside the cabinet because the compressed air goes back to near atmospheric pressure keeping the relative humidity of the cooling air low.  One nice feature about the cooling effect of a vortex tube cooler that is often not noticed is that its cooling effect depends only on the temperature of the compressed air. So even if very hot environments, for example right next to a hot furnace, as long as the compressed air temperature is reasonable, it will cool very effectively.   It is very difficult to install a vortex cooler badly. It is simply a matter of putting in a standard knockout hole on the control panel, installing the unit, adding a hose with punched holes (to distribute the cold air around the panel quickly), and then let it operate. An optional thermostat with solenoid can turn the air on and off as needed to conserve energy.  A major application is for variable frequency drives (VFD’s) where the cooling is normally needed only on startup only so energy use is actually quite minimal and very cost effective.  The harsher the factory environment, the more vortex coolers become economical as they do not break down in such environments nor do they have the extra maintenance the alternatives require.

A solution to Refrigerants’ Flammability

Air conditioners are everywhere, in homes, cars, office buildings, and even factories. They are also used to cool small enclosures, in particular electrical and electronic control panels. It is these small enclosures that this article will focus upon. Air conditioners utilizes refrigerant. The original refrigerants were CFC’s or Chlorofluorocarbons which are highly stable compounds that were also used as propellants in spray cans and in refrigeration and air conditioning units.  Unfortunately, due to that stability they were found to deplete the ozone layer and were replaced by hydrochlorofluorocarbons (HCFCs). HCFCs and hydrofluorocarbons (HFCs) that came right after were created as substitutes for CFCs for use in refrigeration and a wide variety of manufacturing processes due to the lower effect on the ozone layer. HFCs have little effect on ozone but contribute to global warming. All of these classes of compounds either destroy the stratospheric ozone essential to life or contribute to global warming, international agreements have been signed to eliminate their production and use by the year 2040.

One of the problems with the new refrigerants is that most are flammable. For example, Flammable refrigerants are illegal to use in an automotive air conditioning systems. There are some exceptions, such as the new  R1234yf refrigerant, which is mildly flammable but only under certain conditions.  Before we focus on air conditioning of electrical and electronic control panels, let’s look at a major small enclosure use and that is in automobiles. Many automobile manufacturers have approved the product.  However, it is notable that initially Daimler, the parent company of Mercedes-Benz originally did not approve the use of the refrigerant especially when a video that was made public of a test showed the interior of a Mercedes hatchback catching fire after R1234yf refrigerant leaked during a company test.  

Credit Wikipedia : https://en.wikipedia.org/wiki/Side_collision#/media/File:Ford_Focus_versus_Ford_Explorer_crash_test_IIHS.jpg

A thought to keep in mind is what happens if your vehicle is involved in an accident. The A/C condenser sits right in front of the radiator and contains high pressure refrigerant vapor and liquid. If the condenser is ruptured in a frontal collision (which it often is), high pressure flammable vapor will be released, almost guaranteeing an underhood fire! So presumably re-designs have been implemented to minimize any possibility of a fire in case of an accident.  One possible solution to the flammability issue HFC-152a (or other flammable refrigerants) is to add a leak sensor inside the vehicle that warns the passengers if a leak occurs, and automatically opens the power windows to vent the vapors (thus, reducing the fire/explosion risk). Another solution is to redesign the A/C system so that it uses a “secondary loop” to keep the flammable refrigerant in the engine compartment and out of the passenger compartment. With this approach, the refrigerant circulates through an intermediate heat exchanger and chills a liquid (probably a water/antifreeze mixture) that then flows through the HVAC unit inside the vehicle. A recent report from the U.S. EPA says this approach meets its safety criteria, while also being energy efficient. But it does not reduce the risk of fire in a frontal collision, and it still poses a risk to technicians and do-it-yourselfers while recharging or servicing the A/C system. 

Honeywell developed in mid-2018 a product called Solstice N41 (provisional R-466A), a non-flammable and lower global-warming-potential (GWP) refrigerant for use in stationary air conditioning systems. Once on the market, Solstice N41 will be the lowest GWP, non-flammable, R-410A replacement refrigerant available worldwide.  This is significant and would certainly address the flammability issue. But it still has global warming concerns albeit much less. Daimler and others such as Volkswagen also have opted to use CO2 as a refrigerant instead but CO2 requires high pressure systems and of course, CO2 is a greenhouse gas. But these alternatives do deal with the flammability issues.

After all this, there is a second problem with the new refrigerants – cost.  The cost of the refrigerant itself is multiple times the cost of the old ones being replaced – as much or by a factor of ten times. Then there is a cost of material changes and some redesign of the air conditioners themselves.

Now, let’s change the environment to that of a factory floor in a production setting where air conditioners or cabinet coolers or panel coolers are used to cool electrical and electronic control cabinets. The first question is whether it is safe to have a flammable refrigerant used in a device that will be mounted to an electrical device? Design has to assure that a spark from a faulty control does not cause a fire from potentially leaking refrigerant. The second is cost, due to the high cost of these new refrigerants. Replacing refrigerant could be far more common on a plant floor compared to an automobile due to heavier use and also from vibration that the air conditioner may be subjected to.  If the non-flammable refrigerant is used, or if a CO2 system is used, the cost is still much higher than traditional systems used in the past and cooling systems more complex.

What is certain, is the rising cost of traditional air conditioning systems.  An alternative has existed for years and that is vortex tube cooling systems.  These systems like the Nex Flow Panel Cooler use only compressed air to operate, with no carbon footprint, no flammability concerns, no chemicals to replace and virtually zero maintenance.  Their use does require the facility to have compressed air but this is available in most large manufacturing plants. They are used mostly for control panel air conditioning in harsh environments where maintenance costs even on traditional air conditions offsetting the maintenance costs.  With the new refrigerants coming into play, and with their extra costs for refrigerants, and most costly air conditioning assemblies, the very simple design of the vortex tube operated air conditioners become more economical. In addition new vortex tube panel cooler designs are being developed to improve their efficiency and more efficient air compressors are also being offered.   So while at the traditional air conditioning end capital costs go up, the operating costs of vortex tube operated systems is trending downward.

Developments in new refrigerants should be carefully watched as it affects all of us concerning the environment and its impact of manufacturing operations and all other areas where they are used.  But at least for manufacturing, there is a potentially better alternative with vortex tube operated systems like the Nex Flow Panel Cooler.

Both Air Amplifiers (especially the FX40 fixed unit and 40002 adjustable unit) and Ring vacs (of various sizes and materials) are used for gas venting applications. In fact, we have manufactured Teflon Ring Vacs for moving gasses in scrubbers to eliminate the maintenance required with vacuum pumps.

Sometimes the Air Amplifiers are first considered for venting because they use the Coanda effect which moves a large volume of gas. They are excellent in moving atmospheric air for example, in venting an enclosure or chamber in emergencies. 

However, if the gas in question is dirty in any way, and/or the material needs to be moved a greater distance, then the Ring vac is a better choice. 

First, an Air Amplifier is limited to about ten feet (3) meters of conveying. It is more sensitive to back pressure than a Ring vac so the distance is limited. Also, the longer the distance, the less the “amplification”. The Ring vac is much less sensitive to back pressure and can move any vented gas much farther with less back pressure effect. It is used extensively in venting the crank cases of gas transmission compressors for example, eliminating the maintenance and regular checks needed on electrically operated vacuum pumps. Air Amplifiers also need at least 80 PSIG (5.5 bar) pressure to work well in venting while Ring vac may do the job with even small pressures of well under 20 PSIG (1.4 bar) minimizing energy use.

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Second, if the gas being vented contained any particulate that may condense out or in any way deposit inside the conveying unit, this can be problematic with Air Amplifiers. The Coanda profile which makes them operate needs to be relatively clean. If a deposit builds up over time, the Air Amplifier may no longer vent well and perhaps even stop working. The Ring vac however, operates differently and the holes in the “generator” of the Ring vac is well insulated against the movement of the gas and any buildup would take much longer to occur, if at all.

Third, Ring vac units are generally less costly than Air Amplifiers and special versions are easier to make to adapt to special applications. If the particular application requires it, special materials can be used, special flanges can be provided or other attachment variations, and other things can be added to suit the customer requirements.

The above explanations seem to favor the Ring vac but it all depends on the specific application. Always speak to a Nex Flow representative for advice on the most appropriate choice.

The Nex Flow Difference: Why we treat our materials differently?

Nex Flow Air Products Corp. sets itself apart from its competitors by doing a few things differently with the materials that we use in manufacturing our products. While some producers are actually quite similar in product as to how they deal with material, we stand out in four specific areas as to what we do with the materials of manufacture. Differences for Nex Flow are as follows:

1. Anodized aluminum parts
2. Powder coated parts
3. No Plastic in our vortex tubes
4. We do not mix aluminum and stainless steel in our vortex tube packages

Anodized Aluminum parts

We make it a point to anodize our aluminum air knives, amplifier, air jets, air wipes and air operated conveyors.

It is actually much easier (and certainly less costly) to produce these items without anodizing due to the importance of efficient aerodynamic design. When the products are anodized the surface changes, even if the change is very small, it makes it more difficult to keep a flat part flat (i.e. air knives). But, we CAN do and we do it because of the value the anodizing adds benefits to the products.

Anodizing helps guard against the effects of the factory environment on the aluminum. Unprotected aluminum will form a powdering while oxide over time. Anodizing keeps the product looking better and longer even when using dissimilar metals in assembly, stainless shims, stainless screws, with aluminum bodies, it protects the accessories from even minor effects of cathodic corrosion.


Cathodic corrosion can occur in a highly humid environment or if the parts get wet. Dissimilar metals can act like a battery where the more active metal can corrode unless there is some form of protection. You can see this effect, for example, with rust around screws used on some buildings or machines because the screws are of one material while the metal it is screwed into is another. When paint wears away, it leaves unprotected metal that is more electrically “active” than the metal in the screw. By anodizing and protecting our product, Nex Flow ensures that our accessories will last longer and look better over time.

Powder Coated parts

Some of our cast zinc parts, specifically our Air Edger flat jet nozzles and cast Fixed X-Stream Air Amplifier, also have powder coating. It provides a much better finish and look to the product and again, extra layer of protection from the factory environment. Powder coating is an excellent protection in a factory environment. Powder coating parts adds intrinsic value to the products to the betterment of the customer providing a product that is longer lasting look better through time.

No Plastic in Vortex Tubes

Most manufacturers of vortex tubes use injection molded plastic “generators” which are used in the unit to initiate the compressed air spinning effect. Nex Flow machines their “brass” generators for that purpose instead of plastic. While plastic would be much less costly, brass offers a few advantages. Injection molding plastic will have some variations in production, especially as the mold wears out. By machining the metal generators we have much greater consistency with the parts which translates into much greater consistency in performance from one vortex tube to the next. Vortex tubes consist of several parts and of course, each part has a certain tolerance in manufacturing. Nex Flow has very tight tolerances on each part and the generators especially require very tight tolerances. The more pieces involved in assembling a part, the more the cumulative effect on the overall variation in tolerance and therefore performance since the operation of all Nex Flow products are based on aerodynamic shapes.

As the generator is such a critical component in a vortex tube, we recognize the need to use metal instead of plastic. Another advantage of using metal, in our case brass, instead of plastic is that plastic can possibly crack over time. If the compressed air supply is dirty the generator can also build up dirt and engrain itself, hence requiring replacement. The metal ones we use are easily cleaned. Sometimes vortex tubes or their packaged versions are used in very hot environments so the parts must be able to hold up in high temperature areas, especially when not operating. In these cases even competitive units replace their plastic generator with metal. Nex Flow vortex tubes and many of their packages are therefore more flexible in the environments where they can be used. While competitors would charge extra for a special product, our standard product can generally be used instead.

We do not mix Aluminum and Stainless Steel

Our vortex tube packages include tool coolers, mini coolers, adjustable coolers, panel coolers, etc. Of particular importance is the materials used in a panel cooler used for cabinet enclosure cooling and camera cooling. Many manufacturers will use a stainless steel vortex tube packages as a control panel cooler using aluminum housing and attachments. While not a problem in relatively benevolent factory environments, it can become an issue in very humid area or in applications where they are used in wash down conditions. Cathodic corrosion can occur described earlier with dissimilar metals with air knives. On one visit to a customer there was actually a competitive vortex tube cooling system with a big hole on the side of the assembly. Cabinet cooling applications are very critical because you do not want any possibility for moisture getting into the control panel. This is the reason vortex coolers should have the proper approvals to insure this does not happen (such as Underwriters Laboratory testing and approval).

Cabinet Coolers are essentially vortex tubes with a cover and some system to prevent moisture from getting inside of the cover and possibly then into the cabinet. This cover was aluminum and the vortex tube another material. The environment was a relatively wet environment, so over time cathodic corrosion cause the aluminum to corrode and create a hole in the protective cover. Thus, creating a potential risk for water to get into the electrical cabinet. It is for this very reason (preventing cathodic corrosion) that Nex Flow only has stainless steel covers for their stainless steel vortex tubes.

Similarly with all other packages systems, whether they are tool coolers or adjustable coolers, the packages are made with stainless steel only and not a mixture of stainless steel and aluminum.

It’s a Wrap

These are some of the reasons why Nex Flow treats their materials differently. While some of these “differences” in material handling and treatment can be more costly from a manufacturing point of view, they do offer significant added value to the products and a benefit to the customer, and still with a very competitive price.

Wind tunnels are large tubes with air moving inside. These tunnels are used to test models of aircraft or other flying objects on their actions in flight. These models are scaled down versions of actual objects that will be built. Researchers and institutions around the world like NASA, uses wind tunnels to learn more about how an aircraft and spacecraft will fly. But it is not just flying machines that are tested. These Wind chambers are also used to test how an automobile shape, or windshield design will behave in environments with strong winds. Aerodynamics is the study of the flow of air or gases around an object in motion. Essentially these tunnels are hollow tubes with controllable fans at one end to test objects aerodynamics ensuring safety and performance of machines.

Airplane builders use NASA wind tunnels to test new airplane designs.
Credits: NASA

Frank H. Wenham (1824-1908), along with his colleague John Browning, invented the wind tunnel and built the first one in 1871. He described it as “a trunk 12 feet long and 18 inches square, to direct the current horizontally, and in parallel course.”  As a British marine engineer he studied the problems of human flight and had many publications. He also made a huge influence in the development of aeronautics. Their experiments showed that high aspect ratio wings – long and narrow—had a better lift-to-drag ratio than short stubby wings with the same lifting area. Wenham may have been the first scientist to use/coined the word “aeroplane”.  Aviation writer Carroll Gray says Wenham’s work may have been an important influence to the Wright brothers.

As mentioned above, wind tunnels typically use powerful fans. But – it is possible to use Nex Flow compressed air operated Air Amplifiers instead of fans for a miniature wind tunnel. To get the system to work, the gap setting on the Air Amplifiers will have to be increased to approach the power needed for testing even a very small object. Although there are limitations to using compressed air for wind tunnel emulation – they do offer some advantages like having a lower noise level and their ability to be combined with vortex tube technology for testing at sub-zero temperatures.

Powerful fans overcome back pressure created by the length and overall volume in the tunnel. Compressed air amplifiers however cannot be “revved up” like a motor and are subject to this back pressure limiting the length and volume of a tunnel where it can be used. However for very light and small objects, it is conceivable to use an Air Amplifier to operate a miniature wind tunnel.

Air Amplifiers take compressed air that is consumed and converts the pressure normally lost as pressure drop and noise into high velocity and high laminar flow.  With fans you can control this velocity and flow by making the fan turn faster or slower. With Air Amplifiers you have some limited control with input pressure but in a much more narrow range which should suffice for a small miniature tunnel. A common setup at exhibitions is to attach an Air Amplifier to a stand and have the amplified airflow support a beach ball which can be held a few feet above the vertically aimed Amplifier. The object tested in an Air Amplifier operated miniature wind tunnel would have to be in the low weight range of a beach ball to be useful. A powerful compressed air operated engineered nozzle, or a series of engineered air nozzles might be paced at one end of a miniature wind tunnel for more force. After a short distance, the combined airflow could produce enough velocity and flow to be useful for testing small, light objects.   One advantage of both using compressed air amplifiers or laminar nozzle is the lower noise level than you would get from a powerful fan.

Vortex tube technology however, does offer one advantage for a special type of wind tunnel.  A vortex tube is a device which takes compressed air and divides it up into a hot and cold stream.  This cold stream of air flow can go to very low, sub-zero temperatures. Vortex tube commercially are available in air consumption ranges of 2 to 150 SCFM. However, there is no reason that a vortex tube cannot be made much larger to consume several thousand SCFM. In some research applications for wind tunnels it is necessary to study aerodynamics at sub-zero temperatures (i.e. the behavior of military aircraft in arctic or subarctic conditions). A much larger vortex tube consuming one thousand SCFM or even more can produce very cold temperatures of -40 ˚C and even colder if the compressed air supply is cooled further. While it would seem to be uneconomical to use such high volumes of compressed air, that high energy cost is offset by the fact that you do not have to cool the air to the sub-zero temperatures required for testing. Also, the efficiency in the production of the cold temperature actually goes up as you increase the size of the vortex tube. Let’s presume you have 10,000 SCFM of compressed air supply.  With vortex tubes the temperature drop increases (you get colder temperatures) the more air you exhaust at the “hot end”. So if only 30% (3000 SCFM) goes out the cold end to get that -40 degrees Celsius. The cost of cooing 3000 SCFM of a fan produced air flow to that cold temperature using a more traditional means of cooling will be very high. You also will be using refrigerant which will be costly, and need maintenance. In using a special vortex tube you only have the compressors and the wind tunnel taking the flow, at the low temperatures you want. This minimizes any maintenance involved. It is actually a very simple system.

So while there are certainly not a great deal of applications where a wind tunnel is needed that produces such low sub-zero temperature airflow, there are certainly enough when dealing with some military and space equipment applications where aerodynamic tests results under extremely low temperatures are required.  In this case, using a special large vortex tube is a possibility. Such special wind tunnel has been built in the past with very large vortex tube design.   

For unique applications such as the above – Nex Flow has experience in special vortex tube design. Some years ago a two meter long vortex tube was developed for an application (not a wind tunnel however) which used natural gas as the medium instead of compressed air. The parameters of the application had to be addressed to develop the optimum design and the supply gas was at very high pressure. The application remains proprietary but it does indicate that vortex tube technology can be adapted and made effective and economical for special applications where cold temperatures or overall cooling is necessary and where using traditional cooling would not be as effective or economical.

So for wind tunnel applications, Air Amplifiers (and even Engineered Air Nozzles or jets) can apply to miniature wind tunnel for small and lightweight objects. If the wind tunnel requires sub-zero temperatures, vortex tube can be integrated as part of the system. Do note that as these are two different things entirely, you connect a vortex tube to an air amplifier

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When Should I Consider Using Vortex Tubes for Spot Cooling?

Vortex tubes create a stream of cold air from compressed air.  When discussing spot cooling we want to specify that it is a “small spot”, and not a large area such as would be addressed by a big fan for example.  We want to focus on a small area from a tiny “spot” to a few square inches, or to an enclosure which can be much larger to a maximum of around 10 square meters, although there are exceptions.

Such “spot cooling” is needed when heat at that spot is either causing a problem in production or, if production can be improved by cooling. The most common “enclosure cooling” is the cooling of electrical and electronic control cabinets that have potential overheating issues and/or where there are dirt problems due to an unfriendly factory atmosphere inside the enclosure negatively affecting performance and potentially the life of the electrical equipment.

One major “spot cooling” application is the cooling of cutting tools during cutting, drilling, or routing process.  Traditionally cutting fluid is used in machining but there is a slow but steady movement to “dry” or “near dry” machining because of the increased safety and especially environmental concerns involved with cutting fluids. Cutting fluids need to be properly disposed of, so there are costs of not only buying the fluid but also the disposal of the fluid.  One of the reasons progress is somewhat slow in adapting to dry machining is that cutting fluid not only cools, but also lubricates and cleans the machine tool as it operates. This is where mist cooling systems can come in handy because it is not completely dry allowing lubrication but limits the need for cutting fluid. That being said, dry machining is actually necessary for some materials such as glass, plastic, ceramic and titanium. Vortex Tubes produce the cold air which is blown onto the cutting tool to keep heat down and actually produce a better cut and speed up the machining operation.  Often these vortex tubes are packaged with an easy to mount system such as the Nex Flow Tool Cooler. 

In some machining application, as when a hole must be drilled deep into a part, some lubrication is required.  Nex Flow developed the patented Mist Cooler to provide the necessary lubrication by misting lubricant “cooled” by the vortex tube.

There are of course many other systems developed and being developed to spot cool for machining and eliminate coolant using inert gas for example but the vortex tube is also an integral part in many of developments because they only use “air” and cost in comparison is usually much lower.  Cooling gas samples in gas analyzers is another good application for vortex tubes. Industrial camera and all sorts of sensors are used in production more and more, and many of these devices are in very hot areas on a production line. Vortex tubes are compact enough to be used to cool these products and keep them functioning effectively and with no maintenance compared to any other alternative.

Other spot cooling applications addressed by vortex tube technology are numerous and limited only by imagination. Some applications for vortex tubes include cooling the nip roll in a plastic converting process for example to prevent sticking, cooling the head of lasers to prevent heat buildup, setting hot melt adhesives so the glue dries faster and to maximize throughput.

Alternatives in such applications can be much larger in size but vortex tubes are very small. Larger size also typically  translates into larger capital cost. As vortex tubes have no moving parts, their maintenance is virtually zero and as long as the compressed air is filtered, their life is as long, or even longer than the equipment they are used with. Compact, zero maintenance and low cost are the key advantages of using vortex tubes for spot cooling over other alternatives.

Utilizing vortex tube technology for cooling enclosures is another major application.  There are many ways to cool electronic enclosures and other enclosures with traditional air conditioners.  However, factory environments can range from quite benevolent to very harsh. A carbon producing facility will be very dusty.  This dust can easily get into control cabinets and cause havoc to the electrical components inside. The limitation on the use of vortex tubes is the amount of compressed air available in any facility.  The cost is also a major consideration as compressed air is costly. Where vortex tube based products such as the Nex Flow Panel Cooler become an advantage is when the increased energy cost offsets the cost savings in equipment maintenance costs in both material and time, and in offsetting damage to the controls.  It is for very hot, humid or harsh factory environments, that increased energy cost of vortex tube cooling systems can be offset by the savings in maintenance time, materials, disposal of filters and improved control life because they keep out the nasty environment from the cabinet enclosures.

Vortex tube controlled cabinet coolers, like the Nex Flow Panel Cooler, have proper electrical certification to assure that no moisture can enter the cabinet. For example, the Nex Flow Panel Cooler models are available to mount onto cabinets with NEMA 12 (IP 54), NEMA 3R (IP 14) and NEMA 4X (IP 66) classifications.

Vortex tubes for these small “spot” and such “enclosure” applications are both a cost-effective and simple solution where cooling is required.

Nex Flow – Heavy Duty Safety Air Gun

There are many compressed air operated blow guns on the market with the vast majority being ¼” or 1/8” meant for light to medium use in production and cleaning applications. They vary greatly in design and quality of manufacture. Most are simple design that do not take into consideration efficient air flows and many do not even meet OSHA or equivalent standards in safety. Many of these blow guns in the market also do not offer ergonomic design. Obviously these lower quality units are sold primarily on price. For the ones that are well designed, they may be higher in cost but will last much longer and is more comfortable to use.

For this higher quality range Nex Flow has the Easy Grip and Easy Grip Light Air Gun range to offer.

For more heavy duty applications, where more powerful energy is required, a much larger capacity air gun is required.  For this reason, Nex Flow developed the Heavy Duty Safety Air Gun.  It is one of the few compressed air operated blow guns on the market with a ½” outlet connection. The gun is specially designed for those applications where traditional air guns are just not adequate in rugged industrial environments. The gun itself is cast zinc with properly engineered internal design to handle a larger volume of compressed air flow than a traditional, smaller air gun with minimal energy loss.  It has a good ergonometric design so that when you hold the gun, it remains comfortable for any blow off and cleaning application which is especially important for safety guns of this size. Even the angle of the handle is carefully placed so operators can easily aim the gun. The rugged casting is meant to ensure a long lifetime of the product even under heavy use.

But the secret of a good air gun is not just the gun itself. It is also the air nozzle used alongside the gun. Very small air guns may only have a tapered outlet ignoring the OSHA safety standards for dead end pressure. Larger standard air guns will sometimes utilize nozzles with a side hole to release some pressure to keep the air outlet under the dead end pressure levels specified by OSHA. However, these designs are not efficient for saving energy and can also still be quite noisy.  It is far better to use an engineered nozzle which primarily uses the “Coanda Effect” to convert pressure normally lost as pressure drop and noise into a high flow, high velocity and high kinetic energy output.  This is what is used on all Nex Flow air guns. For the Nex Flow X-Stream Heavy Duty Safety Air Gun, the air nozzles used is either the powerful patented Nex Flow Model 47006AMF cast zinc air nozzle or the Model 47006AMFS stainless steel ½” air nozzle. These units are of course also available for use as standalone for production blow off and cleaning applications as well.

Nex Flow’s nozzles are very powerful and yet safe and energy efficient.  Most High capacity air guns comes with up to 3/8” outlets, but very few offer outlets of up to ½”. This larger outlet combined with internal and external designs makes the Nex Flow X-Stream Heavy Duty Safety Air Gun the most powerful with highest flow available. The Heavy Duty gun comes with a composite rubber grip and tailored handle to provide an optimal grip for the user. The force created is 5 to 7 times more than traditional air guns.

There are sometimes hard to reach areas where the Nex Flow “Heavy Duty” Safety Air Gun may be too short. In these situations, Nex Flow has three different extensions available depending on the reach one needs:  6” long, 500 mm and 1000 mm long. They are manufactured of light-weight anodized aluminum. The 500 and 1000 mm long extensions have a quality rubber grip along its length to be able to comfortably support the extension and the nozzle which would be placed at the end of the extension. This allows for the air gun to be used to get into hard to reach areas. For more flexibility, you can insert a swivel in between the extension and the air nozzle. The swivel can be locked into place at the desired angle. This feature combined with the power of the air gun size and safety nozzle makes it extremely flexible to address many different and even difficult to reach applications including cleaning.

Industries that require the Nex Flow X-Stream Heavy Duty Safety Air Gun, are heavy industries such as steel, casting, and pulp and paper plants. While other competitive models (of which there are very few), tend to be costly, our well-designed Heavy Duty Air Gun is relatively low cost yet, efficient and easy to handle.

Using Compressed Air in Packaging

Compressed air is safe, reliable, and used in packaging products. The compressed air systems move materials from one area of the factory to another, perform blow-off, part drying, and align products for packaging. Bakeries use compressed air for blow-off applications, while others use compressed air to clean containers before filling them with products.  Compressed air technology is also used to cut, sort, shape, and convey products, such as food, from one location to another in a factory.

Cartons are also formed, filled, and sealed using compressed air. The quality of compressed air can vary widely depending on its application. The food industry requires the highest level of safe, clean compressed air to handle and package goods. Pharmaceutical industries also require more stringent clean air than other industrial applications because they are either ingested or injected.

Clean, high-quality compressed air is required in pharmaceutical and food packaging to ensure consumer safety and prevent product contamination. It is essential to have either no contact with the product or contact using pure air to avoid product recalls, damage to brand reputation, or litigation. Pneumatic systems are recommended because there is no chance of leaking oil as in hydraulic systems.

Pneumatic systems do not pollute or release contaminants into the atmosphere, so they are especially useful for packaging food products. These systems have no moving parts, so there is less maintenance and downtime compared to other systems.

Using Compressed Air in Packaging

Clean compressed air is essential for food and pharmaceutical processing and packaging operations. Compressed air must be purified, especially when the product is consumed.  Compressed air conveyors are the best technology to ensure safe food quality. Contaminants include spores, solid particulate, vapors, and moisture. Oil is often not an issue with compressed air conveying systems, unlike hydraulic systems, which use oil as a medium.

To stop microorganisms and fungi growth, the dew points of air at line pressure must be -25 degrees Celsius (-15 degrees Fahrenheit). Standards have been developed that state very fine filtrations to prevent particulate and oil from contaminating food products.

How does Compressed Air Keep Products Dry and Free of Contaminants?

Equipment performance is only as good as the quality of air. Any atmospheric air contains some moisture and dirt. No matter how small the contaminants are initially, they are concentrated when the air is compressed as the air heats, its ability to hold water vapor increases. The vapor condenses into liquid when the air begins to cool as it travels downstream. Maintenance by plant operators can remove liquid, particles, and contaminants. Air dryers are installed to reduce moisture.

They lower the dewpoint of the compressed air to prevent water droplets from forming downstream. There are four types of dryers: Refrigerated, chemical, regenerative, and membrane or mechanical. Mechanical filters work with compressed air dryers to remove contaminants and water. There are three types of filters: Particulate, coalescing, and adsorption.

After the appropriate filter has been added to the conveying system to ensure that the compressed air equipment does not introduce contaminants, equipment that is used to blow off products before packaging is added, examples of this type of equipment include engineered nozzles and air knives. They conserve compressed air by using the Coandă effect to entrain surrounding air along with compressed air to create a high-flow velocity stream of air.

What are some things to remember when using Compressed Air Products for packaging?

If used as intended, compressed air will not generate biological, chemical, or physical hazards while packaging goods. The manufacturer is responsible for producing final products that are sanitized and free of contaminants such as oil, microorganisms, particulate or dust. Manufacturers that use the compressed-air system must carefully consider productivity and production costs against safety.

Compressed air used in packaging will often come into contact with the product. “Contact Application” is defined in the British Compressed Air Society (BCAS)/ British Retail Consortium (BRC) code of Practice for Food Grade Air code as “the process where compressed air is used as part of the production and processing including packaging and transportation of safe food production.”  This means that packaging and moving products with compressed air is a contact application.

Other examples of compressed air contacting the product include blowing off the water after washing a product and before packaging, cooling a product to increase line speed, and blowing off excess ingredients (such as sugar) before cooking. Non-Contact Application is “the process where compressed air is exhausted into the local atmosphere of the food preparation, production, processing, packaging or storage.”  Non-contact applications can be categorized into 2 additional sub-categories (high risk and low risk).

Using Compressed Air in Packaging

When designing a compressed air system for conveying, it is important to use filters and air purifiers to ensure compliance with various safety and manufacturing standards. The BCAS/BRC Code of practice recommends testing the machinery installation twice a year for contaminants such as microorganisms, particles (dirt and dust), humidity, and oil contamination. Refer to this article to learn more about the requirements in the food industry or the standards in the pharmaceutical industry.

With regards to filtration, a centralized air drying and filtration system should suffice if the pipes are relatively new in the facility. However – if the pipes are polluted or hard to clean – it is better to have both a centralized filter as well as a decentralized filter installed upstream of the point of use. New or cleaned pipes are also recommended of zinc-plated steel for food applications, V2A/V4A, compressed air-approved plastic, or aluminum.

How does it work?

The Packaging industry includes a wide variety of materials and products since almost every manufactured product is packaged: toys, food, soft drinks, beverages, cigarettes, cosmetics, brushes, kitchen accessories and more. All the products move down the assembly line before packaging. The packaging process consists of transportation lines made of pipes or ducts to carry a mixture of products and materials along a stream of air.

The pneumatic conveyor system consists of interconnected transition lines, hoses, cylinders, a gas compressor, standard cylinders, and gas (atmosphere). The compressor generates the air flow and transmits the material through a series of hoses. Manual or automatic solenoid valves control the air flow—a centrally located and electrically powered compressor powers cylinders, air motors, and other pneumatic devices. Pneumatic systems are controlled by a simple ON/OFF switch.

There are three conveyor systems that generate high-velocity air streams: a suction system/vacuum system, a pressure system, and a combined system.

A suction or vacuum is used to move light-free-flowing materials. The system operates at 0.5 atm below atmospheric pressure.

A positive pressure compressed air conveying system is used to push material from one point to another.  This type of conveyor operates at a pressure of 6 atm or more.

The combined suction/pressure conveying system is used to convey material from several loading points (suction) to deliver to several unloading destinations (push).

What are some Nex Flow products applied to packaging items?

Pneumatic systems are highly recommended when manufacturing, moving or packaging any product that will be digested or inserted in a living organism, such as food or pharmaceutical goods, since there is no chance of contamination due to burst pipes or oil leaks. Nex Flow manufactures compressed air products that help companies to package goods by supplying machines used for industrial cooling (Vortex tubes), part cleaning, drying, and blow-off, and air-operated conveying before packaging.

Nex Flow engineered air optimization design improves safety while increasing manufacturing and packaging productivity and decreasing energy costs.  The air-operated conveyor systems sold by Nex Flow can replace traditional conveyor belt systems, which have higher operational costs because they need to be regularly maintained.

Spot Cooling

Nex Flow pneumatic products provide the best spot cooling and blow-off solutions for materials before packaging.  Vortex tubes convert compressed air into very cold air for spot cooling for industrial applications. Small vortex tube-operated mini-coolers and vortex cooling can provide extremely cold temperatures for spot cooling before packaging without refrigerants, such as CFCs or HCFCs.  Vortex tubes improve factory safety and reduce noise for workers in a manufacturing environment.

Blow-Off Products

Effective, engineered blow-off products manufactured and sold by Nex flow include air knives, air amplifiers, air jets, and air nozzles. These products are another example of how Nex Flow strives to improve the safety of manufacturing and factory environments because they meet OSHA noise and pressure specifications. Among many other applications, air amplifiers are used to clean and dry parts and remove chips and part ejection.

Air knives and nozzles are used to flip open and close the tops of boxes during packaging. Air blade ionizers effectively remove static that could trap the dirt while using plastic wrap for packages.

Conveying Systems

Compressed air-operated conveying systems move materials and products at high speeds over long distances.   Ring Vac Operated conveyors, and X-Stream Hand Vac are used for conveying materials where vacuum force is required to move products over long distances at high rates. Ring Vac Air operated conveyors were originally designed to help with bending and lifting goods. The speed of conveyors depends on the density of the materials (lbs./cubic foot), horizontal distance, and vertical lift.

A Ring Vac operated conveyor is a simple, low-cost solution to other pneumatic conveying systems. They are available in several materials depending on the application. Ring Vac operated systems are made of anodized aluminum or stainless steel. 316L Stainless Steel pneumatic conveyors are used when moving food and pharmaceutical products or packaging. It is available in regular and high-temperature stainless steel for high-temperature and corrosive environments.

The X-stream® Supreme Pneumatic Conveying System (XSPC) is an air-operated conveyor that uses compressed air for an efficient and power venturi action along the length of the non-clogging design.   The compressed air system is designed to transport or vent lightweight items and raw materials for packaging at high rates over long distances.

The cost-effective systems are ideal for continuous or intermittent use since they are operated by a simple on/off switch and are controlled by a regulator.  All Nex Flow conveyor systems are simple, easy to install and use, compact, portable, and maintenance-free.

Other benefits of compressed air-operated conveying systems are also reliable since there are no moving parts and low maintenance costs.  These systems have no angles to collect contaminants such as moisture, particulate debris, or microbiological growth. They are safe for any factory environment because the system is powered by compressed air and not electricity.

Mufflers, filters, mounting systems, and static control for blowing off dust and debris from statically charged surfaces are available through Nex Flow to improve factory production and efficiency in assembly and packaging goods.

Trust Nex Flow to provide the most efficient, reliable, maintenance-free compressed air solutions for packaging your goods so that they are clean and safe for your customers.

Using Compressed Air in Packaging FEATURED PRODUCTS

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Vortex tubes are ideal for spot cooling and enclosure cooling.  Typically one vortex tube is used for one “spot” and for “one” enclosure.  But there are some situations where one vortex tube can be split into multiple “spots” as long as one important criteria is kept in mind.  Once the compressed air exits the vortex tube it needs to be directed to the area that needs the cooling.  When the vortex tube is out in the open, this is achieved by adding a delivery tube, usually flexible tubing to direct the cold air to that spot.  When cooling an enclosure, the cold air is sent directly into the enclosure from inside the enclosure. Once the air exits inside the enclosure it can be further distributed around the enclosure thru tubing but all the cold air is input into the enclosure.

Two factors that must be considered when using the cold air produced in a vortex tube: conduction and pressure drop.  The general rule it to keep any tubing on an open space vortex tube as short as possible, preferably under 8 inches. One example where a vortex tube has been used in open space for multiple locations is on routing a plastic part.   Once Nex Flow Model 50030H vortex tube had the cold air split into two directions and delivered to cool two routers. Rather than using one vortex tube for each router, one larger capacity vortex tube was utilized. If two separate units were used, they could have been smaller capacity units (Model 50015H), each which is ½ the capacity of what was used.    What made this work was delivering the air with large (10 mm) tubing to offset pressure drop and keeping the distance as short as possible (under 8 inches to each router). Also, the tubing was insulated to minimize the effect of conducting heat from the surroundings into the tubing, heating up the cold air. There was consideration for using two vortex tubes but there were also space issues with the application.

But this is not a common application.  If the distance they had to cool was much longer from the vortex tube, we would have recommended two of the smaller capacity vortex tubes.  There is another consideration when considering the use of vortex tubes for multiple location cooling. Let’s take the example above. If the distance from the vortex tube was only a few inches more, to get the same cooling effect at the router, we would have had to use a larger capacity vortex tube, a Model 50040H.  That extra 10 SCFM of compressed air use costs energy. That extra energy cost would more than pay for the extra vortex tube in a very short time, and even if used sparingly, certainly in under a year. The increased operating cost, even with minimal use, can easily be equal to or more than the capital cost of one additional unit.

Concerning enclosures, more than once we had to address an issue with cooling when a Nex Flow Panel Cooler, instead of being attached directly to the control panel. Was for some reason mounting off to one side, and a tube was attached to the bottom of the Panel Cooler and then put into the control panel.   Needless to say, the unit did not cool as was expected because the cold air heated up several degrees before it reached the control panel. The Panel Cooler has a built in vent to exhaust the displaced hot air inside the cabinet and of course was not used at all when mounted outside. If you are facing any difficulties with installation – please do not hesitate to contact one of our engineers.

Another thing to remember when installing a vortex tube or a vortex tube operated device like the Panel Cooler, onto an enclosure that it must be installed at the top, or if space is lacking, near the top using a side mount.  The reason is that cold air falls and hot air rises. The reason a distribution tube is used at the end of a Panel Cooler is to distribute the cold air faster to isothermalize the cabinet (even out the temperature) more quickly.  If the vortex tube device is mounted too low, the hot air will tend to stratify at the top of the inside of the enclosure.  

When considering any vortex tube operated device – cabinet enclosure cooler, tool cooler, spot cooler, mini cooler or the vortex tube itself, it is best to keep any attachment at the cold end as short as possible when the product is in open space.  When attached to an enclosure of any type, the cold air should be directed directly into the enclosure, near or at the top.

Compressed air is just not a topic that is taught well in schools. There are organizations such as the Compressed Air and Gas Institute that offer basic courses in compressed air but the topic is just not as thoroughly understood anywhere. One of Nex Flow’s missions is to educate the marketplace about our unique technologies so you can choose the highest quality products for your needs at a fair price.

With the knowledge not generally known by the public – there are biases everywhere with facts both accidentally and deliberately distorted to promote certain type of products. One such example is the promotion of variable drive air compressors where they are sometimes not the best solution. Another such example is with air amplifiers that sometimes claim to have very high “air flow amplification” with high velocity – when in fact the aerodynamic design of the amplifier loses velocity as you increase flow rate. There are a lot of air nozzles on the market that are air amplifiers as well but they are NOT the same. In this article – we will discuss 3 types of compressed air nozzles and how to boost machine efficiency by utilizing the right type of technology and to recognize what to look for when having to choose an air nozzle.

There are essentially three types of air nozzles:

1. Very inexpensive non-engineered air nozzles
2. More costly engineered cone-shaped nozzles
3. Even more costly engineered bullet shaped nozzles

The simple non-engineered nozzles are usually cone shaped but without taking aerodynamics into serious consideration. The outer shape may offer some energy savings – but the inside of the air nozzle also matters. A common air nozzle used in blow guns is where a cone-shaped or even bullet shaped nozzle is used on air guns and a hole is drilled on the side to let out some air so the system meets the OSHA dead end pressure safety standards. These non-engineered nozzles do not really take into consideration noise level and energy requirement.

The first real engineered nozzles were cone shaped and all are basically where compressed air exits at the base of the cone from a complete ring around the cone.  They are a little more costly to manufacture but still relatively low in cost. Yet, even with these designs the noise levels and efficiency can vary extensively. Most of the engineering takes place on the outside but not always on the inside where internal compressed air movement should also be considered to minimize turbulence, pressure losses, etc. which are all determined by internal design. Two cone-shaped nozzles may look exactly the same on the outside but perform radically different because the inside is not the same.  A well designed cone-shaped nozzle like the Nex Flow 47000 series takes into consideration the inside and outside aerodynamic to make the nozzle most effective while reducing noise levels and achieving energy savings compared to open tube for blow off applications. These designs normally produce a moderate force level but very high flow and this mass flow makes them ideal for liquid blow off, light cleaning and especially for cooling because of the high “amplified” air flow. One nice characteristic of a well-designed cone-shaped air nozzle is that they are effective at some distance from the nozzle due to the laminar flow produced.

Finally comes the bullet shaped nozzles which takes engineered design to another level. In this type of nozzle, the compressed air comes out of a series of small holes strategically placed around the bullet shape (as opposed to the base of the cone). Air flow inside the bullet nozzle is also designed to minimize turbulence. The placement of the holes for the compressed air to exit around the outside can control the flow profile of the nozzle. You can make the profile narrow and pointed or wider. The wider you make the profile, the weaker the point force will be (but you will get a greater area for blow off). The sharper the profile, the higher the force. This design allows for a wide variety of nozzle ranges, even for a given size to address many applications not possible with the cone shaped nozzles. In addition this design can produce a higher force/unit air consumption making them more efficient for use where force is more important than flow. The previous cone-shaped designs are better for cooling but the bullet shaped designs are better for cleaning. Typical energy savings are also higher and in the 40% range for cleaning applications. Again, as with all nozzles interior consideration is key to minimize turbulence which maximizes performance and minimizes energy and noise levels. When properly designed – these nozzles also provide great laminar flow, so they can work at a distance from the target. Nex Flow has a patented design for example in their hole design to allow their bullet shaped Air Mag nozzles to work father from the target than any other nozzles on the market. This can be a big advantage in some manufacturing operations.

One version of this type of engineered nozzle uses the so-called Laval effect which is an internal flow profile where the compressed air pushes through an hour-glass shape inside the nozzle accelerating the air at the exit creating a higher force.  However, the air exit and spreads very quickly so these designs use slotted air flows in a rather inefficient manner to squeeze in the spreading air flow. The result is that the force might be acceptable while very close to the nozzle but as you move away they become much less effective.

In general both properly engineered cone-shaped nozzles and bullet shaped nozzles are effective when the flow produced is laminar and are dramatically more energy efficient than non-engineered nozzles, with lower noise levels and can work at a much greater distance.

A blind hole is a hole drilled into a part. A blind hole refers to a hole that is reamed, drilled, or milled to a specified depth without breaking through to the other side of the workpiece. The etymology is that it is not possible to see through a blind hole. In this instance blind may also refer to any feature that is taken to a specific depth. More specifically referring to internally threaded holes (tapped holes). Where cleaning is automated safety is not a big issue because personnel are far from the cleaning zone. But, for manual cleaning, safety is a serious concern that must be considered and addressed.

After a hole is drilled – normally it must be cleaned of dirt and debris. Because a blind hole does not completely pierce through, it is often much more complicated to clean. In order to effectively clean inside the confined space of a blind hole there must be a means to introduce and remove air and or liquid from that confined space. For an “exchange” to take place, one media must be entering the blind hole through the single available access simultaneously as the trapped material exits through the same access. Buoyancy, fluid dynamics and surface tension all come into play. If using a liquid to clean a blind hole some issues must be considered. In most cases, blind holes are first filled with air as they enter the cleaning process. The initial challenge is to remove the air from within the blind hole and replace it with the liquid as the first step in cleaning. If the open end of the blind hole is facing down, the buoyancy of the air will prevent its escape from the hole much like an inverted drinking glass or a diving bell.  

If the opening of the blind hole is up, it allows the buoyancy of the air to cause it to exit the hole depending on the cross section of the hole. This is not a problem with holes that are, for example, 1 square inch in cross section, but as the size of the hole becomes smaller, forces of surface tension can prevent the liquid from giving way to the passage of the trapped air.

So for very small, deep holes using compressed air in many cases can be a better alternative. This is where often air guns with small nozzles are used to blow into the hole and clean out the dirt. In either using air only, or using liquid, the person doing the cleaning has to wear protective clothing and eye/face and body protection because debris may be flying out of the hole as it is cleaned. For this reason some alternative cleaning systems involving air guns have been made.

One common one that has been copied is to use something similar to the Nex Flow X-Stream Hand Vac.   The unit is set in vacuum mode. At the outlet end of the unit a plastic piece is attached. A small tube is inserted into the plastic piece and connected to the opposite end of the air gun which has the air blowing. Therefore the small tube at the vacuum end is blowing air from this tube at the same time the gun is vacuuming. The theory behind this setup is that the small tube blows air into the blind hole and the debris blown out of the blind hole flies up and is vacuumed away by the gun into a collection bag connected to the air gun. The plastic attachment covers the entire opening of the blind hole so that the dirt and debris do not fly onto the person holding the cleaning system enhancing safety.

In real life however it is not a very good system.  First of all, the tube cannot blow very far into the blind hole because it loses force quickly the deeper the hole is.  Second, the vacuum effect works against the force coming from the small tube. The air resistance weakens the cleaning effect.  In turn this also weakens the vacuum effect. So although it is a nice idea….it is not the best way to clean blind holes.

Nex Flow had considered such a system in the past as well since it is easy to convert the Hand Vac to do this. But we did not want to sell an inferior product. Hence the development of the Nex Flow Blind Hole Cleaning System. It can clean all kinds of drilled holes to a depth of up to 525 mm or 20 inches and holes up to a maximum size of 1 inch or 25 mm. The first requirement was to come up with a series of various small diameter extension tubes to be attached to an air gun that would carry compressed air down inside the blind hole.  The exit of the air gun has a rubber attachment that goes over the air tube extensions and which covers the blind hole. There are three different sizes of these “adaptors” each to handle a maximum diameter of hole of either 16 mm, 20 mm, and 25 mm. The adaptor covers the entirety of the hole to protect the user. Being made of rubber it provides a much better protection than plastic. The various lengths of tube attached to the air gun are for various depth ranges of the blind hole.  They are interchangeable as are the adaptors. There is no vacuum required. By inserting the appropriately sized length of tube that delivers the compressed air, the force from the air is more than enough to force the dirt and debris back up and out of the blind hole, thru the air gun and into an attached collection bag.

This system is far superior than the previously described method and actually uses much less compressed air to complete the task. It has proven to be far more reliable, safe, rugged and efficient as well as much easier to use and with greater flexibility. The only drawback is that the diameter of the blind hole is limited by the diameter of the tube extension as you require space around the tube to have the material blown out. However, for some shallow depth and very small diameter bind holes Nex Flow has provided some system where a small tube is used that is just outside the blind hole but covered by the adaptors to clean the parts. But for most applications, even for deep blind holes, it is a cost effective solution for cleaning.

FEATURED PRODUCTS

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Alternative to Refrigerant for Industrial Cooling

One of the major contributors to the destruction of the ozone layer was chlorofluorocarbons or CFC’s used in air conditioning and refrigeration. Work on alternatives for CFC’s in refrigerants began in the late 1970s after the first warnings of damage to stratospheric ozone were published. This led to the creation of Hydrochlorofluorocarbons (HCFCs) which are less stable in the lower atmosphere. This resulted in the redesign of some equipment as well as replacement of materials which were negatively affected by using the new HCFC’s. The main advantage that HCFCs have over CFC’s is that they are much less stable and more reactive with their additional hydrogen atom(s), meaning they can usually break down in the troposphere before reaching the stratosphere and attacking the ozone. The HCFC’s are actually interim replacements for CFC’s because they still deplete stratospheric ozone, but to a much lesser extent. Ultimately, hydrofluorocarbons (HFCs) will replace HCFCs. Unlike CFCs and HCFCs, HFCs have an ozone depletion potential (ODP) of 0. HFCs were developed in the 1990’s as a replacement to the ozone-damaging chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). They are now the most dominant cooling agent in new refrigeration, air-conditioning (AC) and heat-pump equipment.

While most modern-day refrigerants are hydrofluorocarbons (HFCs) – they have recently been scrutinized as being a potent greenhouse gas. a problem. HFC’s are widely used in air conditioning systems and their usage is anticipated to rise, with their negative impact on global warming also being predicted to increase.

So now there are plans to phase-out HFCs in air-conditioning systems and new replacement fluids are currently being investigated but options are limited.

HFCs replaced HCFCs in many AC systems, but even now HCFCs are still used in developing countries. Even though the replacement of CFCs and HCFCs by HFCs reduced the risk to the ozone layer, they still possess enough high global-warming-potential (GWP) to warrant research efforts into finding an alternative solution. Refrigerants are the essential working fluids in a vapor compression refrigeration cycle. They absorb heat at low temperatures in the evaporator and release it at high temperatures through a condenser.

There are only a few pure liquids and blends that have the potential to be used as refrigerants to replace HFC’s.  Most of the fluids that seemed to have potential at first turned out to be classed as flammable or mildly flammable. Six of these slightly flammable, novel molecules were identified, but present unknown risks, are tetrafluorodioxole, trifluoromethanethiol, trifluoropropyne, difluoromethanethiol, (E)-1,2-difluoroethene (R-1132(E)) and tetrafluoromethaneamine. The flammability of course is a problem.  

The other potential is refrigerant blends. 1,1,2,2-Tetrafluoroethane (commercially known as R-134) is a molecule that has been previously considered but was never used commercially. It is now being stipulated that it could be a good candidate for refrigerant blends.   Refrigerant blends are currently being developed and tested, and although they don’t perform as efficiently as pure fluids, they minimize the flammability and in some cases, can remove the risk completely. It is a compromise that is being considered and developed, but it does not offer the ‘ideal’ refrigerant that many people are searching for.   The problems in finding a new pure refrigerant not only lies in flammability. There are also limitations on size, as the thermodynamics only allows for small molecules, of which there are a finite amount. The unknown risks of some molecules promote the apprehensiveness to use such molecules as years of R&D could yield a useable molecule, so a number of people willing to take a chance on these molecules will be low- even if there is potential. Barring the discovery of a fantastic refrigerant blend, or dealing with the flammability issues, if these are the best choices, what chance do we have of efficiently replacing HFCs?   

There is however, an alternative that should be considered at least for smaller applications when compressed air is available in industrial applications. That is vortex tube technology. The vortex tube, also known as the Ranque-Hilsch vortex tube, is a mechanical device that takes compressed air and splits the air flow up in such a way that it exits the tube hot at one end and cold at the other. Invented in 1931 by the French physicist Georges J. Ranque, it was commercialized in the 1960’s and still used extensively to day for spot applications (spot cooling) but also to cool electrical and electronic control panels, in particularly very harsh factory environments. One of the issues with vortex tubes is that they operate using compressed air. While great for the environment (they only use the air we breathe!) the high energy cost of compressed air has to be considered.  In very dirty factory environments however, this higher energy cost is offset by the higher maintenance costs saved when using traditional air conditioners. In difficult manufacturing environments, standard air conditions have to contend with frequent filter changes, higher levels of breakdown and therefore higher repair costs, shorter life, and more frequent refrigerant replacement due to vibration (which only harms the environment more).   Vortex tube technology can actually produce temperatures as low as -40 C or even lower in some cases with virtually zero harm to the environment and require very little maintenance.

Vortex tube technology has not changed much since the 1960’s but is due for efficiency enhancement.  If these devices can be improved in efficiency even modestly, they can be used more and more in at least industrial environments.  Compressed air is not flammable, does not harm the ozone layer and does not contribute to global warming. If a manufacturing facility is using air conditioners for cooling control panels and even for other cooling applications, they should evaluate their maintenance costs, machine life, the internal labor costs to maintain them, and even the cost of disposing used filters. If the cost is relatively high, they should consider vortex tube technology as an alternative. Vortex tubes have virtually zero maintenance and as long as the compressed air supply is filtered to keep out moisture and dirt, the devices have a lifetime of use with zero maintenance. Apart from cooling control panels and any electrical and electronic cabinets, they find use in all sorts of spot cooling applications because they are so rugged and compact.  They are used to cool tooling for example in dry machining. The technology is finding increased usage for machining in the move away from coolant for environmental reasons. CO2 is sometimes used to cool in dry machining but again, you have global warming issues.


Cooling molds with vortex tubes is possible by blowing cold air into the mold cavity. Welds are cooled in metal can production using vortex tubes. Cooling cameras or sensors in factories that are exposed to a hot environment is a major application where vortex tubes are used and provide a great benefit where traditional air conditioning devices would not work well.  Basically any open “spot” or any hot enclosure can potentially benefit from vortex tube technology.

There tends to be a stigma against the use of compressed air due to the high energy cost but when considered against environmental cost of alternatives, and against the traditional capital costs, and maintenance costs, it becomes more and more attractive as time goes on.  Traditional air conditions will become more costly as alternative refrigerants are adopted for the simple reason that their lower stability means change of internal materials and the cost of the refrigerants themselves. Vortex tube technology will only become more attractive, at least for industrial applications. It does not deplete the ozone, does not contribute to global warming, and uses only the air everyone breathes.

In a previous article, we’ve explained why it’s not practical to use vortex tube to cool a room. Another question that gets asked sometimes is – can I cool a small server with a vortex tube and that answer is generally no but it is possible to cool small individual servers. Computer equipment generates heat, and are sensitive to heat, humidity, and dust. If we’re talking about a computer server – there is also a need for very high resiliency and failover requirements. Maintaining a stable temperature and humidity within tight tolerances is therefore critical to IT system reliability. According to OpenXtra, server room temperatures should not dip below 50 ˚F (10 ˚C), and should not exceed 82 ˚F (28 ˚C). The optimal temperature range is between 68-71 ˚F (20-22˚C). So, when you have numerous servers on the premises for your business, heat and power will be some of your primary concerns. A single server can generate quite a bit of heat and when combining several together with other equipment in a closed room, temperatures can quickly add up.

In principle it is easy to calculate the size of air conditioning unit you need for your Server Room, just add together all the sources of heat and install an air conditioning unit that can remove that much. In practice, however it is more complicated.

Fire regulations often require that Server Rooms have levels of insulation far above that of a normal office. Providing sufficient cooling is essential to ensure reliable running of servers, routers, switches and other key equipment. Failure of air conditioning can lead to serious consequences for the equipment itself and for your company. Early warning of problems and spare capacity in the cooling system are both highly desirable.

The amount of heat generated is known as the heat gain or heat load.  The heat load depends on a number of factors, by taking into account those that apply in your circumstances and adding them together a reasonably accurate measure of the total heat can be calculated*.

Factors include:

• The floor area of the room
• The size and position of windows, and whether they have blinds or shades
• The number of room occupants (if any)
• The heat generated by equipment
• The heat generated by lighting

Follow these 5 simple steps to calculate Total Heat Load:

1. Calculate the amount of cooling required depending on the area of the room.
   Room Area BTU/hr = Length (m) x Width (m) x 337
2. If there are windows to your server room – do the following calculation. If there are no windows – then skip steps 2 and 3.
   *note: This if for the Northern Hemisphere. If you are in the Southern Hemisphere swap the conversion factors as the heat on North facing windows is then greatest.
   South Window BTU/hr = South window Length (m) x Width (m) x 870
   North Window BTU/hr = North window Length (m) x Width (m) x 165
   2.1 If there are no blinds on the windows multiply the result(s) by 1.5.
   2.2Calculate heat load for all windows combined.
   Total Windows BTU/hr = South Window(s) BTU/hr + North Window(s) BTU/hr
3. Purpose built Server Rooms don’t normally have people working in them, but if people do regularly work in your server room – you can calculate the heat output if any personnel in the room (around 400 BTU/hr per person)
   Total Occupant BTU = Number of occupants x 400
4. Estimate the Equipment and Lighting heat load. The wattage on equipment is the maximum power consumption rating, but the actual power consumed may be less. However it is probably safer to overestimate the wattage than underestimate it.
   Equipment BTU/hr = Total wattage for all equipment x 3.5
   Lighting BTU/hr = Total wattage for all lighting x 4.25
5. Calculate Total Heat load by adding the above together.
   Total Heat Load BTU/hr = Room Area BTU/hr + Windows BTU/hr + Total Occupant BTU/hr + Equipment BTU/hr + Lighting BTU/hr

This is the amount of cooling required so you need one or more air conditioning units to handle that amount of heat. Generally this load will be quite high for using vortex tube operated Panel Coolers.

So what size of air conditioner do you really need?

Small air conditioning units have a cooling capacity of between 5,000 and 10,000 BTU/hr. Small units may fit in windows, venting to the outside environment. Panel Coolers can provide up to 2800 BTU/hr of cooling. Larger air conditioning units may be rated in tons of cooling. 1 ton of cooling is equivalent to 12 thousand BTU/hr.

While vortex tube operated Panel Coolers can cool a small individual server, cooling the entire room can be a problem for several reasons.  First, a Panel Cooler or a Cabinet Enclosure Cooler that operates with vortex tube technology, works by providing cold air into the item cooled.  But the waste heat is dispelled into the room. If you have multiple Panel Coolers, that can add up to a great deal of heat. The only way to regulate that heat added is to vent that waste heat outside the room from each Panel Cooler.  So the server may be kept cool, but not the room. That waste heat needs to be removed. Secondly, because Panel Coolers use compressed air, a large number of units requires a larger compressor which in turn can add to energy costs.

While it can be practical to cool a small server with a Panel Cooler for cooling a dedicated server room it is generally not practical.

FEATURED PRODUCTS

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Galvanic Corrosion – What it is and how to prevent it?

Galvanic corrosion (also called bimetallic corrosion) is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte.  This occurs in batteries for example where the cathode stays whole and the anode corrodes as the battery is working. Contrary to some believes – Galvanic corrosion does not only occur in water. Galvanic cells can form in any electrolyte, including moist air or soil, and in chemical environments. As an example, Over 200 years ago, the British naval frigate Alarm lost its copper sheeting due to the rapid corrosion of the iron nails used to fasten copper to the hull. The electrolyte in this case was salt water creating a galvanic cell.

In the case of the Alarm, the iron acted as an anode and was corroded at the expense of the copper which acted as the cathode. Just two years after attaching the copper sheets, the iron nails that were used to hold the copper to the ship’s underside were already severely corroded, causing the copper sheets to fall off.

Metals and metal alloys all possess different electrode potentials. Electrode potentials are a relative measure of a metal’s tendency to become active in a given electrolyte. When in the same environment, the more active a metal is likely it is to form positively charged electrode (anode) and the less active metal is more likely it is to form a cathode (negatively charged electrode).

The electrolyte acts as a conduit for ion migration, moving metal ions from the anode to the cathode. The anode metal, as a result, corrodes more quickly than it otherwise would, while the cathode metal corrodes more slowly and, in some cases, may not corrode at all.

The Nex Flow Difference Allowing Products to Last Longer than Competitors

While products such as air knives, air nozzles, air amplifiers, vortex tubes, etc. are not necessarily immersed in any electrolyte, if the environment is humid, or if the equipment is subject to wash down procedures, it is very possible that this type of corrosion can occur.  One example is mixing stainless steel and aluminum. There was one example where a competitive cabinet enclosure cooler was observed with a big hole on its side after some years of use. The stainless steel vortex tube inside combined with the aluminum housing, and the factory environment, over time caused the aluminum to act as an anode and started to corrode.

Nex Flow® takes certain steps and actions to prevent this from happening in their products allowing the products to last longer.  The first is to protect aluminum that is used, especially if combining it with steel or stainless steel. Our aluminum air knives for example – are anodized and as such have a protective coating to prevent an “electrical circuit” with the stainless steel shims used inside and the stainless steel screws used to hold the air knife together. In addition, the aluminum would tend to act as an anode anyway in an electrolytic environment and being so large compared to the stainless steel shim corrosion would be minimized. Regardless of whether galvanic corrosion would occur, the anodization also protects the air knife from any environment which bare aluminum is unprotected.  Similarly, Nex Flow anodizes all their aluminum parts – air knives, air jets, nozzles, air wipes and air operated conveyors such as the Ring vacs. Air amplifiers and flat jet nozzles which are aluminum zinc-cast are powder coated for longer life and also look better.

When it comes to vortex tube technology, such as cabinet enclosure coolers (panel coolers) and tool coolers, no aluminum is used. It is stainless steel with some brass internal parts. This works to ensure that you will not find any holes in Nex Flow Panel Coolers caused by galvanic corrosion ever. So when shopping for products to blow off, clean, move, and cool, look not only at the performance data, design and workmanship – all which are important of course – but also refer to the quality and type of material used in construction. You can also refer to this article on how to avoid galvanic corrosion. Remember that materials used and how they are put together does make a difference.

WHY NEX FLOW RING BLADE AIR WIPES ARE SO MUCH BETTER THAN COMPETITIVE OLD TECHNOLOGIES AND EVEN OTHER OPTIONS

Older technology compressed air operated air wipes are built from UHMW blocks or similar material. These air wipe or circular air knife usually have a hinge to open and close the block around the extruded material which has some air holes drilled into it. With this style it is often tout that it uses less compressed air for blow off. However, in practice you normally need more than one unit. It may take as many as five units of this style to do the same job as a Nex Flow Ring Blade air wipe, so you actually end up using much less compressed air. In addition to being more effective, the Ring Blade air wipes are typically much less expensive and produce even a lower noise level.

Let’s compare a typical situation. Take two units of a ½” UHMW version which uses 8.3 SCFM each or a total of 16.6 SCFM at 80 PSIG.  Units of this design can produce noise levels of 85 dBA. One Nex Flow Model 20000 – ½” Ring Blade air wipe only requires 14 SCFM at 80 PSIG with a noise level of 75 dBA and can easily remove water from an extrusion in a single pass. Only one is required.  The question is often asked “how many do you need” and the answer depends on many factors such as the smoothness and surface tension of the liquid on the surface of the material to be removed, speed and the distance from the air wipe to the material surface.  The 360 degree uniform “amplified laminar flow” of air removes liquid evenly and quickly. 

Nex Flow air wipes come in aluminum with rubber hose connecting each half of the mated semi-circular parts, or aluminum with brass fittings and stainless hose for temperatures up to 400 degrees F and in 316L stainless steel with a braided stainless-steel hose and fittings for temperatures up to 800 degrees F and for highly corrosive environments. Nex Flow Ring Blade can reduce noise levels compared to older designs by as much as 10 dBA.

Old technology plastic block air wipes that are used for larger diameter extrusions tend to be longer and take up more space.  They can still be loud at over 80 dBA as well. The Nex Flow Ring Blade design is much shorter and compact, even for large diameters and can still reduce noise levels significantly while doing a better job in drying with less number of units and less space for each installation.

Blower operated may offer lower energy consumption, but the same issues can arise in blow off.  The biggest complaint from such systems is insufficient drying (just as in the old plastic block design), requiring multiple units, much higher noise levels, and a higher footprint. All this leads to higher capital cost, and increased maintenance which can offset energy savings. When the job really needs to be done, the Nex Flow Ring Blade is an obvious choice.

FEATURED PRODUCTS

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The Nex Flow air wipes use a special series of Coanda angles to convert noise and pressure drop high velocity flow. The angles and even the positioning of how the air exists the plenum chamber and goes over the angles can make a difference.  One of the factors to consider is something called “blowback”. This is where the air existing the air wipe can actually reverse flow at some point. Some designs similar to the Nex Flow Ring Blade do not seem to take this effect into account but we do. Each Nex Flow unit is designed to avoid this “blowback” effect and perform optimally when drying extruded parts.

NEX FLOW RING BLADE AIR WIPE –  COMPACT, EFFICIENT and QUIET and can clean and dry even complex shapes as this photo shows.

Two other important factors should be considered when comparing designs similar to the Ring Blade:  One is that Nex Flow always uses stainless steel shims to maintain the air gap for longer life rather than plastic shims used by competitors.  Secondly, all aluminum Ring Blades are anodized (most competitive units are NOT), again for longer life and metal protection. Stainless steel units are not just 303/304 stainless but are higher quality 316L stainless steel making them the best choice for applications like drying medical tube extrusions.  All this at generally a much lower cost.

When using Nex Flow Ring Blade air wipes for all sorts of extrusions their design can even address complex shapes such as EPDM profiles like the trim on an automobile.  The angled high velocity flow will get into corners and crevices to help dry in many cases, even at high speeds.

So when considering air wipes (air knives arranged in a ring shape), and even when checking existing systems, the things to consider are the number of unit being used (or being considered to use), space or footprint cost, noise levels and actual (or expected) performance.

Air Amplification Explained compressed air-operated amplifiers presume to reduce compressed air use and lower noise levels in blow-off and cooling applications. The term air amplifier is normally applied to annular-shaped units (called Air Amplifiers or Air Movers).  However, the same technology used applies to air nozzles, air jets (which are essentially small Air Amplifiers), air knives (linear amplifiers), and some air wipe designs.  

They work using the Coanda effect, which essentially is an effect in which a fluid (liquid or gas) clings to a surface as it flows in a laminar flow.  You can see this effect by turning on the water tap in your kitchen at a low level, so the water flow is smooth. Put your finger just touching the flow, and it will bend the water flow as it slings to your finger.  The same thing occurs with a compressed gas like air.

To achieve the best use of this Coanda effect other factors need to be considered such as the volume of the chamber that the compressed air exits to minimize any turbulence inside the chamber and minimize pressure losses.  The number of and actual angles of these Coanda “angles” combined with internal designs where the compressed air is collected before exit determines the overall efficiency and performance of the compressed air used for blow-off. 

As this air bends, it creates a vacuum behind it drawing in surrounding atmospheric air. This “converts” the pressure that is normally lost as pressure drops and noise into the flow. This is important. Several things occur as this additional mass flow is drawn in and mixed with the compressed air. 

First, the overall force goes down because you mix with still (non-moving) atmospheric air. Secondly, the flow is dramatically increased because of this pressure conversion to flow. It is “converted energy” instead of “lost energy.” While the overall force goes down, overall kinetic energy remains high and laminar for some distance. 

This means that whatever blow-off energy is required, it can perform that operation at a greater distance from the exit of the air than if compared to an open pipe or tube. And, of course, because lost energy is recovered, the noise levels drop. So when we state that air amplification is free, it is quite true, but with the caveat that overall force will be lower, but velocity and flow will both be much higher, all due to the extended laminar flow. 

If air is blown with just an open pipe or tube, the exit creates a great deal of turbulence resulting in energy loss and high noise levels. This means that the force may be quite high near the exit, but it will dissipate quickly as you move away from the air exit.   

There are some situations where high pressure is required. In those situations, an air amplification nozzle or device may not meet that force, such as removing heavy mud baked onto a surface or breaking off scale waste from metal.  But the pipe used has to be close to the surface. However, except for those situations, air amplification technology certainly can be used instead, as the vast majority of applications where compressed air is used do not need the full high-pressure force of an airline.  

One suggestion to reduce energy and noise is simply to reduce air pressure for blow-off and even cooling applications. After all, a 20% reduction in compressed air pressure will reduce the compressed air energy by 10%. If you reduce the pressure to 30 pounds from 80 pounds per square inch, that would yield a 25% reduction in energy.  Noise will go down somewhat, but you will still have a great deal of turbulence at the air exit, and you will not get the “distance” for effectiveness that you would with an air amplifier.

But, even an air amplifying air nozzle will get anywhere from 30% to 40% or more energy reduction with the equivalent force, depending on the design of the air nozzle.  For example, older cone-shaped air nozzle designs will reduce energy by 30% and create very high flow and velocity, which is especially ideal for cooling applications. The Nex Flow Air mag design reduces energy by over 40% and works with a powerful force and high flow, and high velocity with the laminar flow at a very long distance, as well as noise reduction.  

The argument for that extra “free” energy from air amplification is therefore very compelling.

As was hinted at above, it is not just the flow profile and Coanda “angles” which affect performance.  It is the internal design of an air amplifier and how the compressed air behaves internally that is also important.  Minimizing internal turbulence is a major consideration in design. For example, you can take five different cone-shaped air nozzles from different manufacturers, test them side by side, and their performance and efficiency can vary by a wide margin. 

In this case, efficiency can be defined as the force produced at a set distance divided by air consumption. There is a design called a Laval nozzle, for example, that was developed to produce less noise and improve energy. However, the noise level improvement is not significantly noticed due to the noise frequencies obtained, and the distance of effectiveness appears to be limited because, to make this design work, the efficient exit of the force-producing airflow has to be contained by a rather inefficient series of air flows from slots around the Laval opening, offsetting any other improvements.  

The Coanda design combined with proper internal design appears to be the optimum methodology in air amplifier design.

Air jets are another example where the Coanda design makes a big difference.  Air Movers or large annual Air Amplifiers, if very small, are called Air Jets.  Most manufacturers of Air Jets have one Coanda angle to direct the air exiting the annual plenum.  Nex Flow Air Jets have several specially designed Coanda angles and can produce the same high level of force and flow with 25% less energy and lower noise levels.

Large annual Air Amplifiers also have efficiency variations among different manufacturers because of internal and external design differences.   A somewhat abused term that often comes up with annular Air Amplifiers is “amplification ratio”. One should be very wary of, frankly, ridiculous claims of high amplification ratios. For example, for annular air amplifiers, the maximum practical ratio you can achieve is about 20 to 1.

This means that if you measure the flow at the exit of an annular Air Amplifier, the flow rate would be 20 times the inlet air.  For several reasons, some producers are claiming as much as 25 times, which is dubious. One reason is that when surrounding air is entrained with the moving compressed air exiting the opening in the Air Amplifier, “still” outside air will slow down the flow velocity at the outlet.

If you entrain, for example, 25 times the compressed air consumed, the velocity would be 20% less than it would be if the figure were only 20 times. That is significant because you need adequate velocity for both blow-off and cooling.  Secondly, the explanations one can read on how this extra air amplification occurs should be challenged as defying physics.

In comparison, Nex Flow has done with such products, the results were a lower air amplification and even lower overall performance because of internal design and extra pressure losses internal to those systems. Anyone can always compare a Nex Flow Air Amplifier to another and see the difference. Nex Flow fixed Air Amplifiers, for example, claim 16 times amplification with a compressed air supply at 80 PSIG (5.5 bar) pressure and at standard atmospheric conditions. 

These figures are averages because air amplification will go up (as much as 20) at lower inlet air pressure and if the atmospheric air is warm.

Air knives are another area where figures need to be considered between manufacturers.  Air knives are linear air amplifiers. There are two styles of compressed air-operated air knives on the market.  The older style uses several Coanda angles where the air exits a gap, normally maintained using a shim to set the gap, and is bent 90 degrees. 

This gives a decent air amplification ratio of about 10:1 right at the exit and 25:1 to 30:1 measured 6 inches away (due to downstream air entrainment) depending on internal design effects.  Some manufacturers have air knives with two gaps and claim as much of a 50:1 amplification ratio (two gaps, so they double the ratio) which makes dubious sense. You don’t double the air out and the ratio – it does not make sense to have it “additive.” 

So again, it is good to challenge claims that may seem to make sense. Another thing to consider, especially with air knives, is real efficiency. Efficiency, as before, is the force measured at a distance per unit of air consumption, for example, force/SCFM. Internal design can make a difference.  Newer style air knives have the airflow exiting straight out of the gap with air entrainment from special angles on each side of the air gap.

This design will provide 25% more force/SCFM than the older style versions, where the air bends 90 degrees. Hence their popularity has largely displaced the older style, but there are still some applications where the old style is useful.  But even among the new style, design differences can affect performance and efficiency.

Nex Flow, for example, with their Silent X-Stream Air Blade air knife has a different internal design than two other significant air knife manufacturers and has about the same force/SCFM as them at a given pressure except for one thing… Nex Flow produces the same SCFM and same force at 60 PSIG, while the other units get equal performance and efficiency at 80 PSIG.  That means a Nex Flow air knife needs less pressure to do the same job as the others.

It was quite humorous when one manufacturer claimed in a blog that our air knives used so much more air at a given pressure, but without mentioning the force produced, a poorly written defense of the fact that they are less efficient. 

If the Nex Flow unit replaced the competitive unit, the air pressure could be reduced by 20 PSIG. As mentioned earlier in this article, that pressure reduction represents a 10% energy saving. So when comparing products, it is very important to look at all the facts. One of the other aspects of the Nex Flow Silent X-stream Air Blade air knife that dramatically illustrates efficiency is how quiet it is, even compared to other designs of its type. 

One other point to mention is the flow profile.  When an air nozzle, air jet, air amplifier, or air knife produces the amplified airflow, the profile will affect the force per square inch or square millimeter.  This is particularly important in air nozzles. You need to decide on the minimum force required and the surface area you need to address.

This is especially important if putting together a row of nozzles for blow-off.  You want the flow profiles to cover the required area without missing any spots or overlapping. A wider profile produces less force per unit area than a more focused air nozzle.

Air amplification is free, but among different designs, it can be more or less free than others.   Besides reducing energy and noise, it is important to remember that air-amplifying products work at a greater distance than just open pipe or tubing. 

The velocity produced by air amplification products is very important when used for cooling. The high velocity combined with the high flow is important, but they are mutually dependent.  The more flow, the less velocity. The less velocity, the more flow. If the velocity is too low, you will not get the same cooling effect. Think of driving a car on a hot day with the window down. 

It’s the same volume of air coming in to cool you, but the velocity from driving fast helps cool you more. But most certainly, air-amplifying products reduce energy use, and noise levels and make factory operations using compressed air more environmentally friendly.

Static electricity is an imbalance between positive and negative charges in materials.  Most people have experienced it in everyday life whether it be with their laundry being “clingy,” making a balloon stick to a wall after rubbing it on your clothes, or when walking with socks on the carpet and getting a small shock from the doorknob. All objects are made up of atoms which have positive and negative charges, like charges repel each other (positive-positive, or negative-negative), while opposite attract each other (positive-negative).

Static attraction and Repulsion

Static electricity is a result of an imbalance between positive and negative charges when two objects or materials come into contact. The surface electrons (charges near the surface of the object) try to balance each other while the two surfaces are together. Let’s say there’s object A and object B. When object A and object B are touching, “A” gives up electrons and becomes more positively charged while “B” collects the extra electrons and becomes more negatively charged. When the two materials are separated, an imbalance occurs with the surface of “B” having a surplus of electrons and the surface of “A” having a shortage of electrons. These charges build up when they don’t have a direct path to the ground, and can eventually build up enough to cause a spark to a nearby grounded or less charged object in an attempt to balance the charge.  

In various industries – this can cause issues with static charge knocking out sensitive electronics near the statically charged area, cause curling in plastic web processes that can cause jamming of machinery, or charged materials attracting dirt causing cleanliness issues in packaging, coating and painting operations.  It can also be a nuisance and even a danger to personnel if being subjected constantly to static charges, especially if the charges are high.

Static charge is best eliminated just before the problem created by the plastic occurs.  For example, if the problem is dirt on a part, it is best to eliminate the static “before” the dirt is attracted to the part.  Sometimes it is not always possible to do that in which case the dust must then be removed. In such cases you can use an anti-static devices coupled with a compressed air operated air knife or air amplifier (ionizer bar in the case of an air knife and spot ionizer in the case of on amplifier). These products “ionizes” the air from the blow off units that bombard the statically charged surface with alternating positive and negative ions, which combines with the opposite charge on the surface of the part thereby eliminating the static charge.  This makes it easier to blow off the dust. Nex Flow examples would be the Air Blade Ionizer and the Ion Blaster Beam.  Normally dust can be blown off but if sticky, the force may not be enough and wiping may be necessary.  Blower systems can also blow off dust but they need much higher volume and stronger ionizing systems due to turbulence. (Compressed air systems provides laminar flow and work better with ionizers).

When the problem is not dirt, and the anti-static device can be close to the problem area, no blow off or air is needed, only the anti-static device itself.  Today the most common static removal technology is still AC technology. Normally, these static removing devices need to be very close to the part unless air is supplied which allows it to be a bit further away (and of course can also clean).    Nex Flow also has an extra powerful AC ionizer for longer distance mounting and also if the static charge is extremely high for better static elimination. There are also now DC systems which operate farther away than AC systems from the target. They are also effective in blow off and cleaning of statically charged parts.

Two measurement devices are important when trying to control static electricity. One is a voltage measuring device such as the Multicheck which indicates if there is adequate voltage at the “pins” on the ionizer which generate the static removing ions.  This will confirm if the static removal system is working. If the voltage is below the normal level it could be from either dirt buildup on the device and cleaning is necessary or there is damage somewhere in the system. The other is a static meter.  Nex Flow has a lower cost and a more accurate higher cost version depending on the needs of the particular application. The static meters measure the static charge on the part before and after application of the static removal action. This will indicate if the system works as required.

Nex Flow has many years of experience in static control and can address any application where static may be causing issues in production, safety and/or cleanliness.

Choosing the best Spot Cooler

What are Spot coolers and their Importance?

Spot coolers are self-contained air conditioning systems that have all the components of larger air conditioning systems but are compact and easy to move.  Spot cooling for industrial applications are used short term to cool a small area on a part or in an enclosure – such as a cabinet. Spot coolers are ideal for cooling electronics, computer server rooms, and humans in small confined work environments. They are often praised for their portability, ease of use, and installation.

Fans cannot cool below ambient temperature because they cool by moving air and cool a wider area.  Compressed air amplifiers cool better than fans because of the higher velocity but they also do not cool below ambient temperatures. Air amplifiers also cool a wider area. This blog discusses the three most popular ways to cool below ambient temperature, namely Vortex Tubes, thermoelectric, and cryogenic gas (CO2 and Nitrogen Gas) cooling systems.

It is important that the spot cooling system chosen is reliable because sudden or frequent break downs can cause costly equipment damage, repair, or replacement.  Keeping humans cool in a small work area is important as well for health and safety concerns. All Spot coolers come with accessories that allow you to direct the cooled air where it is needed most.  Any condensation that results from the cooling process is drained through a hose or bucket.  

Vortex Tube Cooling System

Vortex Tube Cooling systems are powered by compressed air. The vortex action separates the compressed air into extremely cold and hot streams.  The cylindrical form causes the compressed air to rotate at a high speed (reaching 1 million rpm). A small portion of the air exits through a needle valve as hot exhaust. The remaining air is forced through the center of the incoming air stream at a slower speed. The action of the slower moving air dissipates any remaining heat into the faster moving air. The super-cooled air flows through the center of the generator and exits the cold air exhaust. Depending on the temperature and pressure of the incoming compressed air, it is possible to achieve cold end temperatures as low as – 40 and even – 50 degrees F.  The hot air (end) can be up to 260° F (127° C).  The Vortex cooling system, or cold end of the Vortex Tube, is often used for “spot cooling” of cabinets, such as control panels and industrial cameras.

Vortex Tubes normally come with the “hot end” adjustable to control the flow and temperature out the cold end.  The more flow out the hot side, the lower the temperature out the cold side.  The cooling effect (BTU/hour) is determined by both flow and temperature drop. Therefore, for cooling applications, the cold end should be between 60% – 80%.  If the cold temperature is most important, then the flow out the cold end should be under 50%.

Choosing the best Spot Cooler

Factors in selection:

Vortex Tube cooling systems that use compressed air is considered where conventional enclosure cooling by air conditioners or heat exchangers is not possible. Ideally, Vortex Tube cooling systems are used to cool small to medium size enclosures, nonmetallic enclosures, and areas where the size of cooling devices is restricted. 

For optimum cooling results when using a Vortex Tube cooling system, the following items are required when installing:

• Clean, dry, oil-free compressed air 
• 80 to 100 PSIG / 70 degrees F or below. Lower pressures and higher temperatures will reduce BTU/H ratings.
• A 5-micron water and particulate removal 
• A 5-micron oil removal filter when oil is present
• Thermostats or temperature indicator sticker
• Valve (optional)
• Muffler go minimize exhaust noise

Advantages:

The Vortex Tube cooling system has many advantages. The small, portable, light weight, and compact system creates extremely cold air without refrigerants, included CFCs or HCFCs.  It is exceptionally reliable since there are no moving parts and virtually maintenance free. It uses minimal electricity (only for the compressor). Vortex Tube cooling systems are useful in harsh and high temperature environments. Customers can expect a long life from Vortex Tubes because Nex Flow uses only Stainless-Steel with a brass generator. Compressed air is not the only gas that can be used to produce cold air, Nitrogen and other natural gases that can be compressed can be used as well.

Applications:

Vortex Tube cooling systems can be used to cool:

• electronic and electrical control instruments
• machine operations/tooling
• CCTV cameras
• Set hot melt adhesives
• soldered parts
• gas samples
• heat seals
• environmental chambers
• workers wearing protective gear
• data centers
• plastic machined parts and molded plastics
• Electronic components

It is understood that cold and hot gas (bi-product) is generated when using a Vortex Tube cooling system.

Choosing the best Spot Cooler

Thermoelectric Coolers (Peltier Effect)

Thermoelectric cooling (TEC) became a viable option for spot cooling in the late 1950s with the development of semiconductor materials. The thermoelectric cooler (TEC), often called the Peltier module, is named after Jean Peltier who discovered heating/cooling effect when passing electric current through the junction of two conductors in the early 1800s. It is a semiconductor-based electronic component that functions as a small heat pump.

Using a low-voltage positive DC voltage to a TEC, electrons pass from one element (p-type) to another (n-type), and the cold-side temperature decreases as the electron current absorbs heat, until equilibrium is reached. The cooling is proportional to the current and the number of thermoelectric couples. This heat is transferred to the hot side of the cooler, where it is dissipated into the heat sink and surrounding environment. The result is a quick and large temperature differential.

Factors in Selection:

To use Thermoelectric spot cooling, a DC voltage required. This type of spot cooling is ideal when refrigerants are not desired, and space is limited.  It a cost effective, reliable, efficient way to spot cool. Multiple thermoelectric coolers are connected side by side and then placed between two metal plates.  It is ideal for intermittent heating and cooling applications because TEC seamlessly switches between heating and cooling.

Advantages:

Thermoelectric spot cooling has come to dominate certain applications because of the following benefits:

• Precise temperature control and stabilization to 0.01 degree C
• reliable
• noise-free operation
• vibration-free operation
• scalable 
• compact

Choosing the best Spot Cooler

Applications:

TEC is used for spot cooling for the following applications:

• Telecommunication applications:
  • 980nm and 1480nm Pump Lasers
  • Digital Transmission Lasers
  • Planar Lightwave Circuits
  • Optical Channel Monitors
  • CATV Transmission Lasers
  • Avalanche Photodiodes
  • Wavelength Lockers
• Medical samples
• Cold storage
• Electronic cabinets
• Self-powered appliances
• Small scale refrigeration
• Harsh environmental protection for critical components
• Computer microprocessors and robotics
• Cabinet cooling

Cryogenic Cooling (Carbon Dioxide or Nitrogen gas)

Cryogenics is the scientific study of materials and their behaviors at temperatures well below conventional refrigeration.  The word comes from the Greek cryo “cold” and “genic”, which means “producing”. Cryogenic temperature ranges can be reported using any temperature scale, but Kelvin and Rankine scales are most commonly used because they are absolute scales that have only positive numbers.  The U.S. National Institute of Standards and Technology (NIST) considers cryogenics to include temperatures below −180 °C (93.15 K; −292.00 °F), which is a temperature above which common refrigerants (e.g., hydrogen sulfide, freon) are gases and below which “permanent gases” (e.g., air, nitrogen, oxygen, neon, hydrogen, helium) are liquids. At 250 F below zero, many gases are liquid.  Below is a list of temperatures where these gases boil. 

Before the fluid’s temperature rise, all the liquid must boil away and turn into a gas. None of these gases exist naturally as a liquid. Each of the gases are cooled to put them into a liquid state.

Latent heat absorption during the phase change from solid to liquid or liquid to gas causes cooling in the immediate area. According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), liquid CO2 (LCO2), known as Refrigerant R-744, is the most widely used method used during vaporization of a liquid to a gas. When liquid CO2 is introduced to the system through the nozzle of a spray gun or cooling injector tube on a temperature chamber or thermal platform (cold plate), the liquid quickly turns to solid state CO2 or dry ice. As the dry ice warms up or sublimates (direct change from solid to gas), a great release of the latent heat occurs.

Liquid CO2:

Spot-cooling method uses liquid CO2 injected in controlled pulses through tiny capillary tubes inserted into hard-to-cool areas to the same level as the rest of plastic mold cores. This approach is meant to complement conventional water cooling by ensuring uniform mold temperature without hot spots. 

When the cooling cycle begins, LCO2 is fed under high pressure (approximately 850 psi (58.6 bar)) through the thin, flexible stainless-steel capillary tubes with solenoid valves to time injections and to the points where cooling is required. The high sublimation energy of the CO2 from solid to gas phase, along with the resulting cold gas, provides a very high local cooling capacity. The CO2 withdraws heat from the steel of the mold and escapes out of the expansion room in gaseous form through an annular gap between the hole and capillary tube. 

Liquid Nitrogen:

Under normal atmospheric pressure, Nitrogen can exist as a liquid between the temperatures of 63 K and 77.2 K (-346°F and -320.44°F). Below 63 K, nitrogen freezes and becomes a solid. Above 77.2 K, nitrogen boils and becomes a gas.  Since it is obtained from the atmosphere, liquid nitrogen is inexpensive and is rarely refrigerated. It is kept in insulated containers called Dewars and can boil away. 

Advantages:

Given the purity of LCO2 supplied for this application (typically >99.98%), there is little danger of residue build-up or contamination of the hole as there would be with water cooling.  Meanwhile, Liquid Nitrogen is colorless, odorless, and tasteless. It is an Inert element that is noncorrosive and does not support combustion, so it is safe.

Disadvantages:

There are several risks involved in cooling using cryogenic cooling systems. There is always a risk of asphyxiation, frostbite, or burns if not used and handled properly.  Cryogenic gas has large expansion ratio for evaporation. For example, if one liter of liquid nitrogen can result in 700 liters of gas. If released in a small room, it can fill a room and make it an oxygen deficient atmosphere. It is also not safe to digest. It is essential that all the liquid nitrogen is evaporated before ingested otherwise it can boil and cause damage to internal organs.

Choosing the best Spot Cooler

Factors in Selection:

Cryogenic spot cooling systems are ideal for specific applications in automotive, medical, aerospace, consumer products, plumbing, and construction.  CO2 is the preferred coolant for spot cooling because it is cheap to capture and compress. It is also ideal for large scale applications due to lower volume cost and longer storage times. The cooling requirements should be above -50 C. For repeated cooling, CO2 must be supplied at the right pressure and at the right temperature without gas bubbles. It stores longer than liquid nitrogen gas, which is stored at -190 C.  

Liquid Nitrogen cryogenics is colder and has greater heat removing capabilities below -60˚C. Proper supply and control system design is crucial because if too much coolant sublimates to a solid state at once, blockages in the cooling system can occur.

It is highly recommended that oxygen monitoring equipment is used to test for oxygen deficient atmospheres during cryogenic spot cooling. The system must be properly maintained to prevent blockages. 

Applications:

Applications of cryogenic spot cooling include:

• Cooling of construction mold
• Preserve experimental samples
• Coolant for computers
• Medicine to removed unwanted skin, warts, and pre-cancerous cells
• Instantly freeze food and cocktails – creating an impressive cloud of vapor or fog when exposed to air. 
• Internet searches will find recipes for nitro-caramel popcorn and pumpkin-pie ice-cream
• Plastic and rubber deflashing and grinding
• Metal treating
• Biological sample preservation
• Pulverization

Summary

Vortex Tube cooling system is a low-cost choice for industrial applications. Simply adjust the hot end hot air valve to determine the temperature at the cold end. The more air escaping from the hot end reduces the temperature of the cold air flowing from the other end of the Vortex Tube. 

It produces cold air instantly for enclosed environments.  Since there are no moving parts, there is no spark or explosion hazard.  Vortex Tube cooling system have two types of generators that are easily interchangeable. One generator has a cooling effect while the other one restricts the flow of the cold air, which creates extreme cold temperatures such as -40 or -50 F. Apart from special designs, the technology is available in the following configurations:

• Packaged Frigid-X® Panel Cooler for cooling control panels
• Packaged as an adjustable spot cooler
• Packaged as a tool cooler or mini cooler
• Packaged as a mist cooler

When you need require extreme cold temperatures, Nex Flow recommends using the Frigid-X® 50000C series. Nex flow vortex tub cooling system consists of a stainless-steel body with all metal parts.   The cooling system is quiet and instantly creates sub-zero cold air temperatures from an ordinary compressed air supply for spot air cooling applications where precise adjustability of temperatures is important.

Like the Vortex Tube cooling system, Thermoelectric spot cooling is an ideal choice for intermittent cooling/heating applications.  The disadvantage is that TEC requires a DC voltage because multiple thermoelectric coolers are connected side by side and then placed between two metal plates. Although equally effective for cooling to extreme temperatures as Vortex Tube or thermoelectric cooling systems for many industrial applications, cryogenic cooling appears to have the highest risks and the greatest need for monitoring equipment for health and safety concerns.

Nex Flow specializes in research and development of cooling technology required for industrial fic applications, such as spot cooling.  Nex Flow® stays ahead of the competition by finding new applications for this unique technology, and to improve the efficiency of the products which depends on many proprietary factors. Corrosion-resistant, food-grade stainless steel means that all Nex Flow equipment is dependable, and long lasting.   All spot cooling equipment is precision machined, assembled, and tested. Manufactured to withstand extreme temperatures and environmental conditions, the Vortex Tube cooling system is produced under strict quality control, which ensures years of reliable maintenance free operation.

Hollywood Special Effects with Nex Flow® Compressed Air Accessories

Not only have Nex Flow® products been used for Hollywood special effects for US made movies but also for movies made by other jurisdictions and for special effects in museums and in theme parks.

The most popular products used are the air knives and the air amplifiers for creating special effects where wind or heavy air flow needs to be simulated. The advantage of the Nex Flow air knife design is its high efficiency in being able to produce more flow and force at a lower pressure than competitive units (performs the same at 60 PSIG compared to competitors operating at 80 PSIG).  The Nex Flow Fixed Air Amplifiers as well as more efficient than competitive designs by about 10% and are much more rugged for easier handling and use.

One unique application in a Stephen King movie was the use of a standard air knife which operates by having the compressed air exit the air knife, and bending 90 degrees over a series of angles.  When aiming a flame source against the flow, the air bends the flame also 90 degrees. With some computer manipulation this simulated a barrier against a flame (bending it 90 degrees).  

One of my favorite application is from the original X-files series filmed in Canada.  The fixed air amplifiers were used to simulate heavy air flow as one of the characters (Mulder) in the X-files was taken by aliens from an airplane. That was simulated by using several AM125 units (now the part number has been changed to FX125).

Standard air knives (Model 10024 – 24” long units) have been used in the Keanu Reeves remake of The Day The Earth Stood Still.  If you have seen the movie there are several scenes where the grass is rustling from the wind. This effect was created using the air knives.  Because of its even air flow it made a realistic simulation of wind blowing over a large area that was filmed.

Product has been used even off camera.  In one of the James Bond movies (the most recent James Bond with Daniel Craig) there is a scene where there is a sand storm and the cameras that were doing the filming had protected the camera lenses with air knives that acted as a barrier to prevent the sand from hitting the lenses.

We do not always know what the specific application is for the product.  Several 2” Fixed Air Amplifiers were purchased by a special effect company in Brazil but we were not told of the scene.  In 2018 some products were purchased for apparently a major superhero movie but we were advised that we could not disclose the details. Needless to say, I will be viewing all the superhero movies for clues on where the products might be applied! While it might not be as exciting as appearing in a movie, having your product in a movie is kinda cool!

It’s not only movies that use Nex Flow products.  A large number of 4” Air Amplifiers were purchased a few years back by Universal Studios when revamping their special effect “wind from King Kong’s breathing” at their King Kong ride. They replaced product previously supplied by a competitor with the superior and better priced Nex Flow product.

Museums are also trying to have exhibit that are more interactive. One such museum approached Nex Flow to use a small air amplifier or air jet to simulating the effect of bats flying by people in one of their bats tunnel.

The advantage of using the Nex Flow compressed air amplification technology is the portability, ease of use and also the quiet non-disturbing operation of the products.  The compressed air is supplied by a compressor in the film studio or from a rented portable compressor when filming on site.

Ring Vac® air operated conveyors were also used by one special effect company but in this case we were not advised of the special effect. We suspect it may have been used to simulate the firing of a projectile of some sort.

Regardless of the particular special effect, there are many uses for compressed air accessories in the entertainment industry, whether for films, television, theme parks or interactive displays in museums. The application of Nex FlowTM compressed air products for blowing or conveying is limited only to the imagination. The low cost, compact nature, portability, and low noise level of the products make them attractive to use in creating special effects.

Vortex tubes are devices that take compressed air and spins it inside the unit creating a spinning air flow in one direction and spins the air flow back in the opposite direction within the first spinning air flow. Part of the air flow is out one end and gets hot, and the internal spinning flow that is let out the opposite end gets cold. It basically acts like tube in tube heat exchanger.

Air input the vortex tube is normally 80 to 100 PSIG (5.5 to 6.2 bar). The air exiting at each end of the vortex tube goes back to atmospheric or at least to a much lower pressure.  In considering what you can or cannot attach to vortex tube, you must first consider these realities:

1. You need a pressure difference between the inlet air to the unit, and the exit points.  If there is no significant difference then the system will not work.
2. The percentage of the air out the cold end is called the cold fraction. For example, if 80% of the inlet air exits the cold side the cold fraction is 80% and the hot fraction (air out the hot side) is 100-80 = 20%.  If you add anything to the cold end, there will be a back pressure. This will affect the cold fraction by pushing more air out the hot side thereby reducing the cold fraction. So there is a practical limit of how much back pressure can be tolerated by attaching anything to the cold end. The ultimate limit is a back pressure that pushes all, or almost all the air out the hot end negating any effectiveness for cooling.
3. Similarly if you attach something to the hot end there will be back pressure pushing more air out the cold end.  The limit would be if all the air is pushed out the cold end – it negates most or all of the cooling effect.
4. Because compressed air exit at both ends, and at a pressure close to atmospheric pressure, a vortex tube is intrinsically safe from over pressurizing, the ultimate supply pressure limited to material integrity (in the case of Nex FlowTM made products, to 250 PSIG).

So when attaching any other accessory to the vortex tube the concepts above need to be considered.  Rarely is any attachment made to the hot air exhaust end except for muffling accessories with minimal back pressure. Even in pre-packaged vortex tubes such as Tool Coolers or Panel Coolers, back pressure is very minimal and typically balanced at the cold end with other attachments such as hose hits or air distribution hose with similar back pressure effects, essentially balancing the system. However, if you examine more closely the cold end attachments, which tend to vary the most, there is a limit there as well. When attaching a hose kit such as locline or similar type of hose, the longer the length the more the back pressure.  Locline hose is used extensively with Tool Coolers. The general rule is to limit the locline to 12” and under and to make sure the opening nozzle has at least a 1/8” opening.  This keeps the back pressure low. Also, the longer you make this attachment, the air will tend to warm up more because of the conduction of atmospheric temperature through the plastic hose to the inside. So practically, the longer the hose, the higher the temperature (less cold air) exiting. In the case of a control Panel Cooler, there is a hose distribution kit supplied which is basically a long PVC hose with a muffler to attach to the end.  Instructions stipulate to create inside this long hose to have at minimum of four (4) holes of 1/8” diameter drilled into the hose to let the air out and blow the cold air from the vortex tube onto the hot parts inside the cabinet. This accelerates the cooling of the inside of a control panel.  Again, the minimum number of holes is required to minimize the back pressure (and also to help iso-thermalize the control panel faster). If the holes are not drilled, the cold air will exit only at the exit of hose end and with the added back pressure will restrict the flow, hence negatively affect the overall cooling rate (slows the process of equalizing the cabinet temperature). The hose addition onto a Panel Cooler also acts as a backup in case of a very remote possibility of any moisture getting into the panel in the very rare case that the filter on the inlet air fails. There are instances where a vortex tube has a hose attached to the cold end to deliver cold air at a long distance for other applications.  It is important to simply use a larger inside diameter hose, the longer the length to minimize back pressure and if possible insulate the hose from conducting heat into the hose, warming up the cold air travelling inside. Care should be taken that the cold end hose is not fully plugged because while the back pressure will force air back out the hot side, any weakness in the hose may also cause it to split and may be dangerous as a result.

The question frequently arise is if it is possible to attach a vortex tube cold air output to the inlet to a blow-off accessory like air knife or an air amplifier (or any other air amplifying or conveying device).   The answer is – it cannot be done simply because of the back pressure requirement of the vortex tube (#3 above). Any air amplifying device requires the air inlet to have high pressure.  For a vortex tube to work, the air exit pressure from the vortex tube must be low.  So attaching a vortex tube to the air amplifying product will just not work.

But…. the possibility of an alternative approach does come up.  There have been a few attempted applications, where the air exiting the cold end of a vortex tube is placed near the air entraining end of an air amplifier such as an air jet or small air amplifier like an FX10, or FX20 or even an FX40.    Successful results are rare however, and not confirmed, due to how air amplification technology works. The air drawn in by an air amplifier is depends on the amplifier size. For example, an FX10 will amplify air flow about 6.5 times and consumes 4.9 SCFM at 80 PSG.  That means it will draw in a volume of 27 SCFM. (6.5-1 = 5.5 multiplied by 4.9). So if you place a vortex tube cold end “close” to the air entraining end the amplified air can be cooled. Even then, much of that cold air will already be mixed with warmer atmospheric air reducing the cold temperature.  And, at the outlet of the amplifier about another 3 times the air is entrained from the warmer atmosphere. Assuming basic adiabatic mixing the cooling effect of the vortex tube supplied air will be greatly reduced. With a larger amplifier, the overwhelming effect of the high volume of entraining atmospheric air overwhelms cooling effect of the small volume of cold air from the vortex tube. This is why mixing the two technologies rarely works.

Air amplifiers and even air knives themselves do cool however, and are used extensively (especially air amplifiers) to cool very hot materials such as castings using the wind chill effect.  It’s like driving with the window down in your car while driving on a hot day. The high velocity of the amplified air will accelerate the cooling of the hot surface because the high flow and high velocity of the amplified air cuts through the heat boundary layer on the part to remove the heat fast.  One example was from an application in Mexico where small, hot aluminum parts which normally cooled in 30 minutes from sitting on a table were cooled in under a minute using a flow amplifier alone.

Vortex tubes are designed to cool enclosures or for spot cooling and not for cooling large areas.  In those applications you are best off using air amplifiers. Therefore, combining vortex tubes with air amplifiers however is not a proven method. When using vortex tubes – it is important to understand the above 4 facts governing the operation of the technology.

Compressed air nozzle – air saving nozzle or engineered blow off nozzles are good to have but there are so many of them. This is why many people get confused and stick to the same products they are familiar with even if there are more efficient versions out there. Worse yet, in some cases engineered nozzles are not used at all and open pipes and tube are used. The price range for nozzles also vary tremendously in the market. The problem stems from a lack of compressed air knowledge to make a proper decision.

In a recent Compressed Air Best practices article, there was an example of a company that reduced compressed air cost by over half – the biggest saving was actually in replacing compressed air jets and pipes with proper engineered nozzles. This alone indicates the tremendous importance to keep compressed air costs low.  Another reason to choose a well designed nozzle is noise level. The exhaust noise from compressed air from open pipe is very loud – not only uncomfortable but also very dangerous to personnel. A well designed unit can reduce this noise and meet the OSHA standards for safety (dead end pressure must be less than 30 PSIG). You get energy reduction, noise reduction and safety.

But how do you choose the best compressed air nozzle?  Do you choose the cheapest? The most expensive? So many designs do look the same, at least on the outside.  But, the fact is, they are NOT all the same – even if they have the same external appearance. Here is why…..

First of all there are two basic designs available – the cone shaped air nozzle which is the oldest design and a bullet shaped design that was first invented in 1989 so it is relatively new. Both designs save energy, are safe and reduce noise levels. The bullet designs focus on noise reduction but also energy reduction and high force. In comparing the two designs the main difference are as follows…

On one hand, the Bullet nozzles gives a higher force/unit air consumption.
On the other hand, the Cone nozzles produce a higher flow output /unit air consumption.

This would imply that for applications where force is more important such as in part ejection the tendency would be toward choosing the bullet design. As for cooling, the flow output is more important and the cone shaped designs would be the wiser choice. Bullet shaped nozzles are more expensive to manufacturer and as a result are more costly to purchase.

Having said that, in either design, the performance can still vary quite dramatically.  For example, we have one customer who tested a wide range of cone nozzles as for the particular application the main criteria was mass flow and not force.  In this case both efficiency and noise were still important as was cost since the customer is an OEM and purchases a large volume. The Nex Flow® unit was the most quiet and the most efficient in both output and energy use. This was despite the fact that all the nozzles tested looked quite similar emphasizing the fact that “it’s not just the outside, but it’s the inside that matters”.

The same applies to the bullet nozzles.  There are endless copies on the market, many claiming performance to be the same or nearly the same as the item(s) they copied. When Nex Flow® decided to create the Air Mag® nozzles a decision was made to make sure they produced the highest force/unit air consumption (SCFM) against all other brands on the market. So at least at this point in time, our Air Mag® nozzle is the most efficient bullet shaped design in the market.  The other goal was to price the units lower than competitive unit with the near, or close performance as the Nex Flow® designs.  Noise levels also had to match or be quieter than other models of the same size. These goal were all achieved giving birth to the first Air Mag® Air Nozzle of the series (Model 47004AMF).   Price and noise level is important and an immediate means for customers to evaluate the quality.  Exceeding or at least matching the performance of any competitive nozzle is important in order to easily replace less performing and/or inefficient nozzles and improve upon the application or match the previous application.

This is because “differences” are far more visible to pressure drop than other products such as air knives and amplifiers when one is replaced with another.  If a competitive unit uses even as little as one additional SCFM to produce the same force, that extra flow can affect the actual pressure entering the nozzle reducing the force and not working as well. We know of one specific instance where a competitor tried to replace one brand with another that was lower in price. While similar in design, the performance did not match up despite claims of equal force in their literature.  What was ignored was the air consumption so the replacement did not work. The Nex Flow® Air Mag® nozzles however would work because of its improved efficiency. This rather sensitive reaction of nozzles to installations from pressure drop tends to be the reason why companies usually opt to stay with the same brand once a decision on the product is made as maintaining consistency in output is important in production.  The Nex Flow® approach allows for customers to easily test and be rest assured that they can replace possibly more costly brands with the lower cost Nex Flow® nozzle with no risk to the production operation.

Additional advantages in the Air Mag® design is more rugged for greater safety and longer life, patented hole design to improve efficiency as well as a sleek body design to keep exhaust noise levels low and allow for the unit to work effectively at a greater distance than other products on the market.  This extra distance can be very important in applications where the nozzle cannot be placed close to a part.

Efficiency in force per unit of air consumption, rugged design, longer distance for effective operation, right pricing, low noise levels and safety are all good reasons to consider the Nex Flow® Air Mag® Air Nozzle.

How was the first Vortex tube Created?

What is a Vortex tube?

The Vortex tube is a mechanical device that separates compressed gas into two extreme temperature air currents.  It was initially named the Ranque-Hilsch Vortex tube, after the names of the two initial inventors. It is also known by other names including: Ranque tube, Hilsch tube, or Ranque-Hilsch tube. The description of this device was originally described in the US. Patent No. 1952281 by Ranque Georges Joseph. A second US. Patent No. 3173273A was filed by Charles D. Fulton.

According to Charles Fulton US patent – it is defined as an “apparatus for cooling a fluid flowing continuously therethrough comprising a housing body having an opening for admitting a gas, a vortex generator supported in said body and receiving said gas, said generator having a plurality of nozzles and a circular vortex cavity into which said nozzles discharge said gas tangentially, a seal at one end of said vortex cavity, a discharge line communicating with the other end of said vortex cavity, and a smaller line for receiving said fluid to be cooled passing coaxially through said discharge line, vortex cavity and seal.”

Using fluid dynamic principles and compressed air, the Vortex tube generates gas at very cold and very hot temperatures simultaneously. Compressed air is fed into a compact T-shaped tube with pipes attached to each side. With a simple internal generator, the gas emerging from the “hot” end can reach temperatures of 200 °C (392 °F), and the gas emerging from the “cold end” can reach −50 °C (−58 °F).  The owners of this device enjoy an extremely long life with very few issues since the compact device has no moving parts. With the simplistic design and parts, the cost to manufacture and maintain the unit is low. There is also no danger of electrocution or fire. The volume of desired gas flow determines the size of the pipe manufactured. It can be used on any type of gas with consistent results. It is the best, simplest, and most direct method to produce hot and cold air.

The exceptional benefit of the Vortex tube is how little gas pressure is required to produce a large temperature difference in the gas streams.

The requirements for the Vortex tube are:

• Compressed Dry gas (otherwise condensation and freezing of moisture needs to be considered)
• Insulated tube

How Does it Work?

Pressurized gas is injected loosely into a swirl chamber and accelerated to a high rate of rotation. With the tapered shaped nozzle, only the outer shell of the compressed gas can escape at that end. The remainder of the gas is forced to return in an inner vortex of reduced diameter within the outer vortex.

The Vortex tube was first explained by observing the geometrical shape and design of the tube and air flow (turbulence, acoustic phenomena, pressure fields). The Vortex tube effect of the compressed gas motion results from the law of energy conservation. The main physical phenomenon of the Vortex tube is the temperature separation between the cold vortex core and the warm vortex margin. It is best described in several steps:

1. The incoming gas is cooled with adiabatic expansion turning any heat into rotational kinetic energy. The total enthalpy is conserved.
   Example of adiabatic expansion is when air rises to the atmosphere and expand due to decreased atmospheric pressure allowing the parcel of air to cool.
2. The peripheral rotating gas moves toward the hot end. Here the heat recuperation effect transfers the heat from the cold slower moving axial flow to the fast moving hot peripheral flow.
3. The kinetic energy from the rotating air turns into heat by means of viscous dissipation. As total enthalpy increases from the heat recuperation process – the temperature is raised compared to the inlet gas.
4. ome hot gas is exhausted carrying with it excess heat.
5. The rest of the gas is funneled toward the cold outlet where more heat is transferred to the peripheric flow. Although the temperature at the axis and at the periphery is about the same everywhere, the rotation is slower at the axis, so the total enthalpy is lower as well.
6. This lower total enthalpy gas is “cold” and leaves the cold outlet.

(https://en.wikipedia.org/wiki/Vortex_tube, Retrieved March 8, 2019)

The vortex cooling is due to angular propulsion.  As the gas moving towards the center gets colder, the marginal gas in the passage is “getting faster”. The more the gas cools by reaching the center, the more rotational energy it delivered to the vortex and thus the vortex rotates even faster.

Compressed gas at room temperature expands to gain speed through a nozzle. It climbs the centrifugal barrier of rotation during which energy is also lost. That energy is delivered to the vortex, which speeds up the rotating air even more. In a Vortex tube, the cylindrical surrounding wall confines the flow at margins and thus forces conversion of kinetic into internal energy, which produces hot air at the hot exit.

The limiting factor for producing the extreme temperatures is high gas pressure to create the extreme temperature changes in the tube.

Who Invented and Improved the Vortex tube?

Georges-Joseph Ranque (7 February 1898 – 15 January 1973) was the inventor of the Ranque-Hilsch Vortex tube. He was born in France in 1898.  At a young age, Georges became interested in physics. In Paris, he studied physics at the Ecole Polytechnique. Afterwards, he pursued a postgraduate degree at the Conservatoire des arts-et-métiers. His initial interest in the operation of the Pantone carburetor led him to study vortices. One of the applications he used the vortex effect was a vacuum pump. His intention was to use his invention to remove dust from a steel plant.  While studying the flow of air through a pump, he inserted a cone at one end of the tube, where air was flowing in a vortex and discovered that the stream of air could be split: one hot and the other cold.  In 1931, he filed the US. Patent No. 1952281.

wikipedia: Georges-Joseph Ranque (7 February 1898 – 15 January 1973)

Ranque described his tube as having a counter flow and a uniflow type. Through his research he determined that the counter flow tube was more efficient. The counter flow Vortex tube consisted of:

• A long slender tube with a diaphragm closing at one end of the tube and a small hole in the center of the diaphragm.
• One or more tangential nozzles piercing the tube inside the diaphragm
• A throttle valve at the far end of the slender tube.

On the other hand, the uni-flow Vortex tube is similar in structure to the counter-flow Vortex tube, the significant difference is that the uni-flow tube has two exit holes in the same end. This tube appears to have lower efficiency than the counter-flow tube because of the mix of cold and hot temperature flows at the same exit. Since Ranque’s discovery, the Vortex tube has been the subject of much research and study by the scientific community. The primary focus of research was to determine the factors that caused the thermal separation and to improve the performance of the tube.

Ranque saw the commercial potential of the tube he called “Vortex tube“, which means “tube tourbillion” in French. Unfortunately, compressed air systems were not reliable at the time of this invention. The initial Vortex tube was a commercial failure and Ranque’s firm closed a few years afterwards. He continued to work on other fields of research and the initial discovery of the Vortex tube slowly faded.

The Vortex tube would have remained forgotten if it was not for Rudolf Hilsch, a German physicist, professor, and manager of the Physics Institute of George August University of Göttingen, who is credited with improving the understanding and performance capabilities of the Vortex tube. The important research reported in his 1947 paper, Die Expansion von Gasen im Zentrifugalfeld als Kälteprozeß, emphasized that considerable cooling can be achieved by using the Vortex tube in various applications including refrigeration and cryogenics.  He cited Ranque’s work in the paper but because of a printing error in the footnote, it was difficult for other scientific researchers to locate the previous research. Therefore, the Vortex tube was briefly known as the Hilsch tube. Now, the importance of this paper allowed Hilsch’s name to be included in the name of the tube so that it is now known as the Ranque-Hilsch tube.

wikipedia: Ranque-Hilsch vortex tube

In May, 1947 William Taylor of the National Bureau of Standards published Vortex tube experimental results that described another hypothesis of how the tube works.  When compressed air passes through the entry nozzle, it speeds up and loses heat. The velocity gained results in a loss of heat energy.  This fast, cold air is then slowed as it spirals in the tube. The molecules of gas drop to the center of the tube.  Surprisingly, instead of heating up as they lose speed, they pass their energy to the next outer layer and remain cool. The additional cooling effect is caused by the centrifugal force of the whirlpool.  The centrifugal force “throws air molecules” out from the center so that there are fewer molecules and lower pressure. When the air molecules move from the high-pressure region of the tube to the lower pressure region in the center of the tube, the gas expands and cools.

1953. Westley published a comprehensive bibliography of the Vortex tube in 1954, containing brief development of the tube from 1931-1953.

In 1961, a General Electric engineer, named Charles Darby Fulton studied the Vortex tube carefully and developed it for commercial applications. Between 1952 and 1962 he obtained the following U.S. Patents related to the development of the Vortex tube:

• US2603535A: Liquid spray nozzle Filed July 15, 1952 INVENTER David C. Ipsen, Charles D. Fulton.
• US3208229A: VORTEX TUBE Filed Jan. 28, 1965 2 Sheets-Sheet 2 INVENTOR. CHARLES DA FULTON
• US3173273A: VORTEX TUBE Filed March 16, 1965

The goals of the US. Patent No. 3173273A were to:

• provide improvements in the Vortex tube so that they emit colder gas and a larger fraction of cold gas with increased efficiency for a greater range of applications
• Reduce leaks
• Increased ability to utilize high gas pressures efficiently
• Reduce the cost of manufacturing

His company, Fulton Cryogenics, manufactured Vortex tubes and became the Vortec Corporation in 1968 to expand and improve the Vortex product line for industrial and commercial applications. The Vortex tube was used to separate gas mixtures, oxygen and nitrogen, carbon dioxide and helium. In 1991, the Illinois Tool Works acquired Vortec Corporation to further study the Vortex tube for technological applications.

Research for nozzles lead to improvements in the Vortex tube design. Merkulov recommended the tip area being 9% of the  cross-section of the tube “with the axial width to be twice the radial depth.” He also inserted a cross in the tube and ultimately shortened the length of the Vortex tube and he received a US patent in 1968 (patent number US3522710A – F25B9/04).

The optimum length of the hot end suggested by Merkulov was 8 to 10 Dc (tube diameter).  In 1961, Dr. Parulekar published a paper based on a short Vortex tube:

1. A cylindrical or convergent piece of axial length equal to 6 mm.
2. A divergent truncated cone with axial length equal to 18mm.
3. Cover, which also forms the third part of the hot side is cylindrical and of axial Length equal to 20mm.

Research results determined that the roughness of the internal surface did not affect the results of the tube output – http://engineering-completed-project.blogspot.com/2015/02/project-on-vortex-tube-refrigeration.html

In 2001, Guillaume and Jolly performed a study on a two stage Vortex tube where the cold air from the first tube was injected into a second Vortex tube. They reported that the temperature difference at each stage was greater than would be generated from a single stage Vortex tube.

To optimize the performance of the Vortex tube, multi-stage Vortex tubes have been studied. Dincer in 2011 tried a “three-fold type and six cascade  type Vortex tube systems” consisting of three and six Vortex tubes connected in a series. Through this research, the greatest temperature drop occurred when six-cascade Vortex tubes were connected.

The curved Vortex tube, studied by Valipour and Niazi in 2011, proved that an increased in temperature difference was influenced by the curvature of the tube. The maximum refrigeration capacity occurred at 110-degree curvature. The maximum temperature difference was generated by a straight Vortex tube.

Other types of Vortex tubes that have been studied include Vortex tubes in various surroundings, insulated, non-insulted and the types of fluids used – such as water instead of compressed air, oxygen, methane and other gas mixture.

Experimentation Discoveries

Ranque discovered through extensive experiments that when the compressed air enters through the tangential nozzle and expanded cold air discharges through a small hole in the diaphragm. Simultaneously, hot expanded gas is discharged through the valve. The coldest gas is produced only when a small fraction of the gas is released through the small hole. It is recommended that the valve is opened widely for this to occur. The result is the hot gas cools to become warm gas.  The hottest gas is achieved by closing the valve. Then, nearly all the gas is released through the small hole and is cool.

The two major inefficiencies of this design are:

• Only a small fraction of the gas can be extracted at the lowest temperature
• The amount of temperature depression obtained never approaches that of an ideal expansion engine.

Continued research is required to determine the optimum configuration is complicated and challenging. There could be up to fifteen factors that need to be considered when optimizing the design. Here are a few:

• kind of gas
• gas pressure
• temperature
• rate of flow
• cold fraction to be delivered at a certain lower pressure

The research on Vortex tube also involves the compressible fluid dynamics of turbulent and unsteady flow, thermodynamics, and heat transfer. Westley stated, “Besides its possible importance as a practical device, the Vortex tube presented a new and intriguing phenomenon in fluid dynamics”.

Each of the above factors results in a change in condition for the remaining factors. Research to determine the optimized factors of using a Vortex tube continues because of the fluid and dependent nature of research results.

Applications of the Vortex tube

The Vortex tube invention impacted refrigeration, air conditioning, cryogenics, instrumentation, and controls. The Vortex tube excels in situations such as cooling a worker wearing a protective suite or electronic equipment in extraordinary hot environment. Research is often placed on cold gas because of its greatest importance and number of uses. Vortex tubes are useful where sometime heat and sometimes cooling  of persons or work environments are required. When using a Vortex tube, it is understood that when cold gas is generated, hot gas is also a bi-product.

Nex Flow strives for excellence and improvements in the Vortex tube technology and original design to best suite an application.  Nex Flow provides three standard sizes of the Frigid-X^® Vortex tubes:

• Mini size – uses 2, 4 or 8 SCFM
• Medium size — uses 10, 15, 25, 30 and 40 SCFM
• Large sizes — uses 50, 75, 100 and 150 SCFM.

Depending on the temperature and pressure the compressed air used, it is possible to achieve cold end temperatures as low as – 40 (-40 C) and even – 50 degrees F (-45.56 C).   Vortex tubes are used to cool electronics, machine operations, tools, CCTV cameras, soldered parts, gas samples, and heat seals. Contact Nex Flow expert technicians to help you decide the best Frigid-X® Vortex tubes for your application.

To choose the perfect blow off product for your manufacturing environment it is important to consider the application, placement in the factory, energy savings, health and safety, and finally material durability.

Application

One of the primary criteria for deciding which blow off product is right for your manufacturing plant is the application desired.  This section describes the primary application for the following devices: air amplifier, air jet, air blade air knives, and air guns.

An air amplifier is an air mover that is virtually maintenance free. The primary applications of air amplifiers include cooling, venting exhaust, drying, cleaning, distributing heat in molds or ovens, and collecting dust.

Air Jets entrain large volumes of surrounding air. They are similar to air amplifiers but comes in a smaller size yet are more efficient flow amplifiers than nozzles. These jets cover a larger blow off area than a nozzle and are ideal for part ejection. They are primarily used for cooling, part drying, chip removal, and air assist.

Air Blade^TM Air Knives consist of a body with a plenum chamber, cap, and either a machined gap in the body or a shim to maintain an even gap along the length of the air knife. It uses compressed air for industrial blow off and cooling. The laminar sheet of air created by the unit is often used to replace rows of nozzles or jets to reduce energy costs. Air Knife is most commonly used to dry, clean, and cool. Examples of applications include removal of liquid, dust, and excess oils from flat and curved surfaces, conveyor cleaning, blow off before painting surfaces, and scrap removal.

Unlike any of the above units, air guns are not integrated into the factory line but instead are handheld units for blowing off work surfaces and other applications that require a high force or flow application. Safety blow guns are used to blow off metal chips during drilling operations, removing “stuck” material such as tape, gasket material, caulk, adhesive, paint, and labels. With the addition of air, the detached material is blown away during scraping, keeping the area clean.

Location

Although these pressurized air equipment may be ideal for specific applications, they are sometimes interchangeably used based on space availability, desired orientation, and even the factory environment. It is important to keep in mind that these blow off devices must have room for exhaust. Furthermore, if the device is used by a worker, comfortability and ease of maneuver is key.

The shape and size of the unit are important considerations. Air amplifiers and jets are both circular products but jets are smaller in size than amplifiers. Hence the amplifiers can blow off a larger area but with less force than a jet.

Air knives are straight and vary in lengths anywhere  between 3” to 36” and can be used as part of an automated conveyor system. Air guns, on the other hand, are typically used at work stations. Extensions and swivels of various lengths and gun tips (i.e. nozzle and air edger) are available, making the safety gun a very flexible handheld unit.

Energy Savings

Depending on the required application, finding the best fitting blow off product allows the equipment to do the same job at less pressure. Energy savings is accomplished by finding blow off products that have the highest force/air consumption ratio. Reducing compressed air use and noise levels translates into  an efficient high output air with lower energy use.

Here at Nex Flow^TM – we continuously research and design better engineered products for our customers. For instance – our standard air blades have been proven to reduce energy by 30% – 90% as it is designed to produce the most force over the length at the lowest possible input pressure. Taking it a step further – our silent air knives are designed to further reduce energy lost as noise and is 25% more efficient than the standard design.

The best blow off customized product and technical support is obtained by choosing Nex Flow systems.  During installation, our highly trained customer technical support  advises our customers to install equipment that provides the most accurate blowing angles and direction All Nex Flow compressed air blow off products have a five-year warranty against manufacturer’s defects.

Health and Safety

The most important reason to use Nex Flow® blow off equipment is safety.  Air equipment exhaust can be loud. Noise and vibration that are detected by the human ear are classified as sound. “Noise” is the term to describe unwanted sound. Extended exposure to unwanted sound or at high levels can harm workers and can result in profound hearing loss. Hearing loss can also occur as the result of one-time repeated contact to loud sounds or uncomfortable sound pressure over an extended period.

Occupational Safety and Health Administration (OSHA) sets legal limits on noise exposure in the workplace. Guidelines are available that describe permittable duration of exposure for occupational exposure limits (OELs) for various noise levels. These OELs are determined using a weighted average over an 8-hour work day. With unnecessary noise, all workers should be exposed to OSHA’s permissible exposure limit (PEL) of 90 dBA during an 8-hour work day.  Note: The OSHA standard uses a 5-dBA exchange rate.

Nex Flow takes noise levels into consideration very seriously because we understand that reducing noise levels from very loud and damaging compressed air equipment is important.   Noise levels are much lower when using air nozzles and air jets. The added bonus is that the use of air nozzles and air jets, not only lower noise levels but also lowers energy use.

All Nex Flow blow off products provide noise reduction  in factories to ensure the safety of your workers in a factory environment.

Some Air Gun suppliers do not provide energy effective nozzles or are not safe to use. All Nex Flow® air guns are safe to use,  have energy efficient nozzles, and meet OSHA guidelines for safety.

Reducing unwanted noise can be achieved through using noise-canceling headphones, mufflers on any exhausting air, or by adding low-cost air amplifying nozzles on blow off devices. To further enhance safety in the manufacturing environment, Nex Flow^® monitoring devices can detect sources of noise previously missed or unidentified. Use the Nex Flow Digital Sound Level Meter to accurately monitor noise levels and ensure that high levels of sounds do not exceed OSHA limited standard 29 CFR – 1910.95 (a) which limits an 8-hour exposure of constant noise to 90 dBA.  The maximum hold setting will provide the highest noise level and will update continuously if a higher noise level comes into play.   If you need to keep a record of sound measurements, a complete data logging system is available.

All of Nex Flow blow off equipment provides noise reduction, meets OSHA safety standards, and are safe to use in any factory environment.

Material Durability

Compressed air operated equipment is generally simple to use, compact, rugged, and portable.

To keep our products durable – we do not use plastic shims to save costs like other manufacturers. Nex Flow^TM only uses stainless steel shims to guarantee longer life with still very competitive prices.

It is also important to choose the correct material used to construct the accessories. In a high temperature and corrosive environment, 303/304 Stainless Steel is recommended. The 316L Stainless Steel is recommended for very corrosive or high temperature applications and when the application is food or pharmaceutical grade. Anodized Aluminum is usually suitable for most other application but for oily environment it may be worth choosing the hard-anodized aluminum. Learn more about “Why we do what we do with our materials” here (Link to article).

Nex Flow is the best supplier of blow off products.  Our trained customer service and installation technicians can help you identify the criteria that is most important for your blow off application.  Educating your workers, while performing regular inspections will enhance their work environment, prevent leaks, and extend the life of your blow off equipment. When choosing the best blow off solution, understanding the benefits of a well-engineered Air Knife, Air Amplifier, Air Jet, and Air Guns to withstand a harsh factory environment with safety in mind is important.  Remember Nex Flow is happy to help you and your company to meet all your compressed air needs.

Case Study: Nex Flow Air Knife Making Chicken Nuggets and Delicious Muffins

Making muffins, or any mass food production operation has critical standards of quality that must be met. If cooking or baking is involved the heat needs to be precise and consistent.  Similarly for the ingredients involved in the cooking or baking process.

Nex Flow Air Knives (also called Air Blades) are used extensively to replace drilled pipe or rows of nozzles and jets for blow off, drying and even cooling. As they are compressed air operated the flow rate and blow off force produced can easily and accurately be controlled for any of the applications.

This accurate control with compressed air operated air knives was especially useful in an interesting and unique application involving the baking of muffins that was installed some years ago. The muffins are produced continuously and then placed evenly spaced in rows onto a conveyor. As the muffins move along the conveyor sugar is added onto the tops of each of the muffins before they enter an oven. The conveyor is continually moving.  The nature of the process of adding the sugar caused occasionally too much sugar to be applied to some of the products. As the muffins moved through the oven, the oversupply of sugar would create burnt tops or overly baked tops which were out of specification and had to be disposed of. While they may have been rejected I am sure some would have been disposed of by eager, and hungry personnel on the line in a very humane manner) The operation I must admit, was very pleasant to the smell and I remember it to this day! To prevent burnt tops – a mechanism had to be put in place to limit the amount of sugar on the muffins.

The means to remove excess sugar was achieved by using a stainless steel air knife at very low compressed air pressure. Very little energy was required to remove the excess sugar and it had to be finely tuned so that just the right amount of sugar was removed. The result is a perfect muffin every time. Yummy!!! The air knife needed to have a high quality in control of manufacture to produce the even flow required with low pressure across the length of the web to cover all the muffins. It also had to be in stainless steel as it is being applied in a food processing plant. Since Nex Flow air knives have this necessary high quality control, so no issues arise in this kind of application.

A similar food processing application came up years later at a factory making chicken nuggets. In this operation the company had previously used blowers to remove access breading on the nuggets. The reason is in the same vein – too much breading on the nuggets produces product that is out of specification. The blowers worked fine but very high maintenance is required. This is because the environment had to be cold for processing meat products and heavy wash downs of equipment must be done daily – thus creating this high maintenance environment for blowers. So instead, the plant switched over to using our stainless steel X-stream Air Blade air knives at very low pressure to remove the excess breading. As was with the muffins, it was all done on moving conveyors.   Not only did the compressed air operated air knives perform the job well, it virtually needed no maintenance decreasing quite a bit of the cost.  Because the pressure used was only around 10 PSIG for the blow off of excess breading the energy cost increase compared to what was used with the blowers was negligible. Another benefit was the very quiet operation of the air knife. At 80 PSIG the exhaust air noise level from the air knife is only 69 dBA and at 10 PSIG the sound was barely audible. The savings in maintenance cost, downtime, and personnel time for outweighed the slight increase in energy costs. Years of maintenance free, reliable product is assured with the use of the silent X-Stream Air Blade air knife. The much smaller footprint of the compressed air device replaced the bulky and noisy blower, creating more space and a better working environment for the employees.

In both operations and outlined above, it is important to have clean and dry compressed air. As compressed air makes contact with the food product in both of the above application – strict guidelines must be followed to ensure that the compressed air is free from contaminants with potential health hazards.

The reasons for choosing the compressed air operated air knives in both situations were similar:

First, it was used to improve the quality of the end product and the solution had to be tightly controlled (not too much, not too little). The compressed air solution allowed that to be done with the use of a simple regulator to set the optimum pressure.

Second, a simple and quick relatively low cost solution was required. In the muffin case, just the capital cost involved in getting a blower system would take a long time to get equipment approval, in addition to space considerations. As for the nuggets, the benefit of reduced maintenance and downtime alone, regardless of the extra benefits of less noise and more space was enough to justify the solution.

Third, easy installation, low noise, small footprint, and ease of use with near zero maintenance made the solution. In many processes you can still see open pipe and open air lines being used for drying, cooling, cleaning and moving products, but with very little investment, the process can be improved dramatically using the compressed air technology. Replacing open pipe, tubing, or drilled pipe using compressed air with the appropriate nozzle type from Nex Flow can reduce noise levels by 10 dBA or more. It can improve safety and improve the manufacturing process with paybacks in energy use in less than a year.  When replacing blower systems, the maintenance costs should also be weighed in along with assessing the actual pressures used in the process. Another factor to consider is whether the blow off, cleaning, drying, cooling or moving of part is intermittent. A compressed air solution allows for an on/off switch, wherein blowers system have to be on all the time. This means that compressed air can be used “on demand” to further save energy.

Contact one of our personnel, so we can help assess your application to determine the best approach to improving your operations, in all sorts of industries that involve the use of compressed air. Our goal is to make sure that compressed air is used in the most optimum, most productive, and the safest way in a factory environment.

This is a topic that is worked to death from both blower people and compressed air people with bias so firmly ingrained – it is worthwhile to take a step back and look at this topic objectively.

The compressed air market is growing significantly every year at over 6% with 70% of compressed air is used for drying, blow-off and cooling. On the one hand – blower companies would recommend to replace every such application with blowers based on energy costs. On the other hand, compressed air companies tout advantages but focus on often exaggerated maintenance costs applicable to blowers.

As with anything else, the answer is typically somewhere in between and it truly depends on the factors that are important for your particular application.

With reference to a white paper written some years ago –  Compressed Air Versus Blowers – The Real Truth there are eight factors to consider:

1. Availability of particular energy
2. Space and weight
3. Noise level
4. Application particulars
5. Reliability
6. Energy cost
7. System cost
8. Maintenance and operating cost

To explore these factors in detail you can refer to the above article – but here we will add some additional insights for each of the factors.

Energy Availability: It can be just as costly to install an electrical supply if one is not available while compressed air is. The reverse situation is also true. This initial installment cost should be considered.

Space and Weight: One has yet to see a blower operated air blow gun that is not the size of a missile launcher. Try to imagine a series of blower air guns, each with their own blower (which is necessary as you cannot transmit blower air over long distances as you can with compressed air). As such, many blower systems are large, heavy, and harder to handle taking up a lot of the factory’s real estate. This can add up to a significant cost.


Compressed air operated accessories – on the other hand – are smaller in size and easier to work with because it is simply connected to a compressed air supply. Ultimately – ease of use translates to higher productivity. This is why air tools are more popular over electric tools. Having said that, if space is available and cost consideration favors blower operated system. That might be the option to go with – just remember that space and weight can sometimes be overlooked.

Noise levels in factory environments are increasingly an issue. As more research results come to light on noise effects on hearing this become an important factor in personnel safety and health.   Both blowers and compressed air exhaust can be noisy but compressed air exhaust is easily addressed utilizing engineered air nozzles. These designed parts can reduce exhaust noise significantly for compressed air systems. Blowers operate at lower pressure and higher mass flow making them noisier as a result.  Plus the blowers themselves, being in close proximity can create a cacophony requiring silencers at extra cost for safe operation. Blower suppliers try to downplay exhaust noise by stating that regardless of what energy source is used, you cannot reduce impact noise. This is actually true – but more often than not – it is the exhaust noise that adds significant decibel levels to any blow off, cleaning or drying application.

Application particulars is where both sides play with figures. Promoters of blower systems often fall back on the assumption that the alternate compressed air system will operate at a full 80 PSIG (5.5 bar) pressure all the time. However, this is not always the case. Blower systems often claim that it uses ⅓ of the energy used in a compressed air system. But, compressed air system has the ability to be used intermittently. So at full 80 PSIG pressure cycling on and off and actually used only ⅓ of the time – the energy cost suddenly becomes equal.

Compressed air system can use engineered nozzles, air knives, air jets and air amplifiers – all engineered profiles that convert energy normally lost as pressure drop and noise into high velocity flow to recover anywhere from 30% to even 90% energy used for blow off and cooling. Move over – operating pressure can be adjusted in compressed air system so blowing off at 60 PSIG instead of 80 PSIG can save another 10% of energy. Combing on-off use with line pressure adjustments, if is very possible to save more energy using a compressed air system than a blower system.

Energy consumed aside, in many applications pressure provided by blower systems is often not enough.  Higher pressure output from a compressed air system may be required for the job at hand as blower system will take longer to complete the same task and sometimes not able to complete the task at all.

Reliability: You cannot have a central blower system but you can have a central compressed air system with backup.  If a blower goes down, that blower needs to have a backup system brought in – for each location. If reliability is of great importance, then compressed air wins.

Getting back to energy cost, advocates of blower systems focus mainly on the energy cost compared to constant running, always high pressure compressed air options.  With the advance of engineered air nozzles, air blades, air amplifiers and even pulsing systems that reduce compressed air quite dramatically, the claim of being 1/3rd the energy cost of compressed air does not always hold up. The difference can actually be much less in energy use depending on actual compressed air pressure needed and if there is on-off control where the blowing power is not needed all the time.

Overall system cost is also important. Capital cost of blower operated systems are always higher. You need a blower at each location of use, requiring more backup systems as reliability becomes more and more important. The amortization time needs to be factored in.  Blower suppliers offset the capital cost typically against energy savings with little consideration of the cost of downtime and backup system costs and again, take the worst case scenario for energy cost. Compressed air advocates however, can often overstate the maintenance costs involved with blower systems which is also an exaggeration. So both options need careful evaluation for a true accurate overall system cost.

Finally maintenance and operation cost (apart from energy) are important considerations.  Blower companies point out that maintaining air compressors is also a cost but then try to appropriate the entire cost to blow off operations which is not realistic. Air compressors operate cylinders, instrumentation and other devices apart from blow off and cooling operations. If 70% of compressed air is used for blow off and cooling, then at best you can only appropriate 70% of those compressor maintenance costs to those applications.  On the other hand, you would have more blowers to take care of which means generally much more maintenance cost as well as potential additional downtime costs.

In summary, when comparing the alternate technologies it is important to factor out the bias from each alternative to choose the best system. As an illustration, we had a customer (who has since relocated their operation) that was using blower systems to dry radiators that were produced in the factory. Not only was the drying system very noisy, it was also not drying adequately. The client needed a more powerful compressed air system, so they opted for compressed air operated air knives to replace the noisy blower operated air knives. One of the other complaints was the regular breakdown of the blower which may have been just a coincidence, but nevertheless a costly irritant.  The switchover was successful. When the person who made the change left the company a new person came in who was more focused on energy saving and only that so he went back to the blower system. Sometime later the company switched back to a compressed air operated system and with a couple more switches – they finally ended up using the compressed air devices.

Realistically one has to look at the overall costs involved with each system including effect on output and productivity to determine which one is the best option. The above anecdote serves to illustrate that bias very often affect the choices made. It is important to look at all the factors listed earlier to determine what is best for your operation. Blower operated blow off systems are not always the best nor are compressed air blow off systems always the best.  The first place to start is to review what you need to accomplish and work back from there. List what is important in each situation – is it noise? Do you have the maintenance personnel necessary or have access to them as necessary and the cost? How important is reliability? Energy cost is certainly important but so is productivity and production output.

So the next time you go to purchase a compressed air operated hand held air gun, think about why you are using that instead of a blower operated blow gun as an example. It would seem absurd to replace that compressed air device with a blower system due to the large and heavy size it would be plus having a noisy blower next to you (but considering an energy saving air nozzle for that air gun would be something to think about!). Apply this same logic to your factory overall. Where high flow and low pressure is adequate and the system must be constantly running, where noise not a big issue and where there is plenty of space, probably a blower operated system is the best option.  But when the application for blow off is intermittent, where more force is required to maintain productivity and output, reliability is important and space is at a premium, compressed air blow off might be the better option.

Static can be a major problem in manufacturing processes involving plastic. When producing, cutting or plastic materials and other types of insulating materials, static charge can build up.  Even metals and conductive materials can have issues with dust and dirt (normally insulating materials). The issue is often because when these material has static charges, particulates like dirt will adhere to the surface of the object and become very difficult to remove.

One area of expertise for Nex Flow is the cleaning of material that may be statically charged or having to address dirt issues. Our product was recruited by a factory in Thailand for a very interesting application with plastic pipes. Despite the fact that South East Asia is a rather hot and often humid environment for much of the year, static can still build up and cause issues.

With the plastic pipe, the pipe is extruded and then cut. After cutting – small pieces of plastic waste generated from the cut “stick” to the inner walls of the pipe. The plastic cuttings stick primarily due to static charge and is therefore difficult to remove. At the time, our client was using an normal air gun which was tedious and time consuming to remove plastic scraps. Often the scraps were blown further into the pipe making it even more difficult to remove. Yet the pipe had to be cleaned on the inside prior to shipping.

Initially a Nex Flow 6” X-Stream Air Blade Ionizer – a 6” air knife attached to a static bar. This test was performed manually simply by holding the Air Blade Ionizer at one end of the pipe and blowing into the pipe towards the opposite end where the debris had built up. When the air flow from the unit was blown into one end of the pipe, despite the overall length being extremely long (several meters) the laminar flow exiting the air knife “hugged” the inside of the pipe and carried the “ionized” air flow till the opposite end where the particulate was stuck. The static eliminator bar instantly neutralized the static on the scrap that was stuck to the pipe and literally blew every single piece out that was in the path of the wide sweeping air flow. It was actually quite dramatic. The air flow covered over 50% of the inside of the pipe surface. The inside surface of the pipe is relatively smooth so the debris was not sticking due to any no other reason except static.

So while it worked in a manual test, the next step was to find a way to have this done in the production line automatically and to also have the “ionized air” cover the entire surface of the inside diameter of the piping. To meet both requirement, the Nex Flow Ion Blaster Beam was used. The device consists of a Nex Flow Model FX20 Air Amplifier that has a plastic attachment at the outlet end where “amplified” air flow exits. On this plastic attachment is an Ionizing Pin which makes an “ion cloud” that makes the air flow anti-static. This cloud of ionized air then exists the plastic attachment. The plastic is necessary because if the Pin was surrounded by metal, it will draw away too many ions through grounding, thereby weakening the ion cloud and reducing the overall effectiveness of static elimination by the time the air hits the debris at the opposite end of the pipe. The outlet air flow from the Ion Blaster Beam is conical. Just like the air knife, the air flow is laminar. Therefore when the conical air flow is blown into one end of the pipe, the flow profile of the existing air spreads and covers the entire inside diameter, then “hugs” the inside diameter covering the entire inside surface of the pipe, and continues to the end of the pipe with the plastic dust and dirt and all easily blown. The result is a pipe with the inner surface fully cleaned.

At this point one industry myth that needs to be addressed is often claims that an air knife or air amplifier can always eliminate static at distances like 20 feet (6 meters) instantly. It does not happen that way. As the ions, a mixture of positive and negative charges, travel with the air flow, some will recombine along the way. The weaker this “mixture” is, the more time it will take to reduce or eliminate static charges. If the static charge is high, or the target for removal of static is fast moving, a strong ionizing bar or pin would be needed. Nex Flow has stronger static technology available for such situations. The plastic attachment used in the Ion Blaster Beam, as well as a powerful ionizing pin, results in the speed of static elimination to be up to 30% faster than an air amplifier system that uses a metal attachment. This is significant in high speed or highly static applications. Learn more about static elimination here!

FEATURED PRODUCTS

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The Nex Flow Ion Blaster Beam comes with, so it can be easily mounted on the customer’s pipe processing machine. As the pipe is cut, it rolls in front of the Ion Blaster Beam, which is placed at the end of the pipe. Then the unit is turned on for a few seconds cleaning out the inside of the pipe. Regardless of which end it is placed, the air flow is powerful enough to remove all debris. The force can also be controlled with a pressure regulator. If the unit, for whatever reason requires more force, the air amplifier that comprises the Ion Blaster Beam has a gap controlled by a shim that can be opened to add more shims. Compressed air is conserved because it is only used for a short blast in every cleaning cycle.  Overall very little energy is needed. After the cleaning blast, the pipe is rolled out of the way and a new one replaces it then the cleaning cycle repeats.

The Ion Blaster Beam was a very simple solution to eliminated the time needed to manually clean the pipes along with significantly improving the quality. It was easily installed and requires little maintenance (occasional cleaning of the ion pin), and was able to assure that the compressed air is clean and dry with proper filtration.

Both the Nex Flow Air Blade Ionizer and the Ion Blaster Beam are excellent for cleaning statically charged parts. Not just because they have good ionized air but because of the even coverage of the surface impinged upon by the ionized air. This air knife’s continuous gap (continuous flow) is what you do not get when using perhaps rows of nozzles or drilled pipe and the conical shape of the airflow from the amplifier with an ionizing pin covers a wider area evenly. Unlike what a few small holes can accomplish placed around an ionizing pin. So for class A surfaces in particular like you get in the automotive industry, such applications are much better suited for using air amplification technology along with quality static elimination technology.

5 Ways a Tool Cooler is used to Improve Factory Efficiency

A tool cooler is a packaged vortex tube to make it more easily used. A vortex tube creates very cold, and even freezing temperatures from compressed air for spot cooling.  By itself, the vortex tube is quite noisy so accessories to muffle the sound of the device is usually required. The tool cooler consists of a vortex tube with a cold end muffler, and a hot end sleeve (to protect from the heat generated at the hot end) which also incorporates some muffling. In addition, a strong magnet is added onto the unit to easily attach it to any magnet accepting surfaces like a machine or steel table to secure the unit in place. So this “packaged” vortex tube is now quiet, easy to handle and more flexible to use.

Normally a vortex tube by itself has an adjustable hot end plug to control the flow of cold air out the cold and hot ends, and to vary the temperature produced at the cold end. But there is an “optimum setting” that will give you the maximum cooling effect and at the same time keep the temperature just above zero degrees C. This is to prevent any possible freezing in the device should the dew point for your compressed air supply is not very low. For sub-zero temperature generation you should have dry air with a dew point below that of the temperature you wish to produce in the vortex tube.

1. The most common use for a Tool Cooler is of course for cooling the tool used for drilling, grinding, milling and routing especially for materials that are not allowed to have liquid for cooling for various reasons like the liquid being detrimental to the material or for reason such as avoiding contamination. This would be for plastics, glass, ceramics, titanium and other special materials.In fact there is an entire movement to replace coolant normally used as much as possible due to the high disposal cost of coolant and for environmental considerations. Much has and is being driven towards dry or semi-dry machining which involves significant machine design changes as well since liquid coolant not only cools, but cleans away the chips and waste produced in the machining operation.
   Tool coolers or variations such as our mist cooler, which offers some lubrication are becoming more popular. But for materials that have always been dry machined such as plastics, the benefits are faster machining (shortens production time and increases output) and better quality, especially with plastics as it produces less waste in the cut (a much cleaner cut). Tool life can be extended as well in carbide tipped tools because the cold air produced helps prevent micro-carbon cracking.

2. Setting Hot Melt Adhesives is another common use for the tool cooler. When applying adhesives, the cold temperature helps to set the glue faster and allowing for a faster throughput. In one application (which I cannot detail due to secrecy), has a continuous line of adhesive applied and required rapid cooling which several tool coolers along the length of the process was able to provide. The customer utilized adjustable vortex tubes prior but the problem was actually personnel continually adjusting. As such, some devices were adjusted for higher flow, some for colder temperature but – what slipped the mind is – consideration for the cooling effect change. Our tool cooler is set for optimum cooling and took this issue out of the equation. Nex Flow do also offer adjustable spot coolers in cases where some temperature control is needed.
3. In line slitting, is a variation in tool cooling in that you are applying the cold air flow to a cutting blade in a slitting operation. The advantage here is not for increasing output, but to have the sharpness of the blade last longer. There is a very noticeable improvement when thicker material need to be slit as the blade would have to work harder and can heat up more. The vortex tube operated tool cooler keeps the temperature down, and extends the blade life. As with the adhesive application, the tool cooler is preset to give the optimum cooling effect to prevent tampering with the unit and maintaining consistency in cooling to control the quality of the adhesive application.
4. Laser cutting is an application where the tool cooler is very effective. For the laser processing of materials, the material changes in the heat affected zone (HAZ) is an important indicator for quality in microelectronics manufacturing. In laser cutting you focus beams to heat the surface of the material up to a high temperature to melt the material and you want to minimize the HAZ. The cooling from the tool cooler decreases potential burning in the heat affected zone area thereby improving quality. As there is no refrigerant involved, there is no effect on the environment. The low temperature cooling air diminishes the HAZ in laser cutting for glass fiber reinforced composite materials for example.
5. Chill roll nip cooling is where the Tool Cooler is placed on the nip roll of a plastic film web processing line. Nip rollsor pinch rolls are powered rolls that are used to press two or more sheets together to form a laminated product. The high pressure created at the nip point brings the sheets into intimate contact, and can squeeze out any bubbles or blisters that might cause a defective bond. If the material is too warm it can stick and if the material is very thick or cooling is uneven, there could be a hot spot causing defects which is easily eliminated by using a Tool Cooler.

In all these applications there is no requirement for lubrication. However, there are applications where some lubrication is absolutely necessary.  One example is drilling a deep hole into a material.  Without some lubrication to the cutting tool, it will bind inside the material being drilled. For this reason Nex Flow developed the patented Mist Cooler which operates not by cooling the tool directly, but by cooling the lubricant applied to the cutting tool to a very low temperature. The liquid is applied as a mist to the cutting tool to provide both the lubrication and cooling it needs. The benefit is the diminished volume of liquid needed to both cool and lubricate. Reduction in chemical use can be as much as 20%, a significant savings even over a short time frame.

Tool Coolers are available in various capacities for cooling depending on the nature of the material being cooled, the rate of throughput and the thickness of the material. There is even a small capacity unit called a Mini Cooler which is used in cutting thin material, and even in sewing operations involving heavy textiles such as jeans and burlap bags where the sowing needles heat up and deform or break thread. The mini cooler keeps them cool. While it is generally a good idea to avoid any adjustable system (as the fixed systems are preset for optimum cooling), the Adjustable Spot Cooler is another packaged vortex tube, very similar to the Tool Cooler but with an easy hand adjustable knob to vary the temperature at the outlet that is available. This is usually used in laboratory applications and for testing where temperature variation is required. Tool Coolers (and other variations) can be specially made to provide sub-zero temperatures if required. The versatility of the Tool Coolers makes it an excellent packaged option for all types of spot cooling applications.

In the previous blog, we focused on tips to prolong the life of your compressed air accessories. Today we will discuss the importance of establishing an inspection routine for your entire compressed air system along with a checklist of items to inspect.

Benefits of Regular Inspections

There are significant returns on the time you spend to inspect your compressed air system regularly. It just takes a little organization to collect detailed information and track changes. This data will encourage and direct your team to perform preventable actions to enhance your compressed air system’s performance. Other benefits of routine inspection include boosting productivity, decreasing waste, optimizing efficiency, seeing opportunities for compressed air applications, and planning for the future. This priceless information regarding efficiency and production, collected just by identifying leaks or areas of potential leaks will allow Nex Flow to recommend cost savings and increased reliability of equipment. It may also encourage your team to simply clean accessories, such as filters regularly.  The knowledge of  the acceptable working range of the gauges will ensure your system is running well. This knowledge can prevent major damage to equipment and prevent costly repair. It will also prolong the life of your equipment.  Simply put, regular inspections will allow your compressed air system to go further, do more, and be more valuable.

Before the Inspection

It is handy to record the equipment data on a tracking sheet before you begin your inspection.  Search through your files and write down the type of compressor, and manufacturer, the model and serial numbers, and flow rating Cubic Feet per Minute (CFM).  Other useful compressor information includes the horsepower at revolutions per minute (HP@RPM) and pressure rating pounds per square inch gauge (PSIG). Determine if the compressor is equipped with a pressure gauge or spring-loaded safety valve. Some compressors have a drain valve while others allow you to remove water and oil.

Know the dryer manufacturer, exit flow rate at the dew point (oC or oF), and model and serial numbers. Record the oil/water separator manufacturer, model and serial numbers, and the flow rate in CFM. Keep these inspection sheets in a binder and refer to them often.

Inspection Equipment

To make easy your inspection, Nex Flow offers leak detecting equipment that makes your routine checks effortless. Ultrasonic leak detectors identify issues before they become costly to repair. Auto drains use solenoid valves for compressed air systems where air could be released to the factory floor.

Once the damage, leaks, or cracks are identified, it is important to assess the severity of the issue and prioritize so that you can improve the efficiency of your compressed air system in the best most cost-efficient way. There are various types of compressed air system inspections: visual, mechanical, calibration, and tests. When performing a visual or mechanical test, it is important to keep track of the condition of the equipment: good, dirty, cracked, etc. The age of equipment is important.  Piping and tubing over time can build up scale and corrosion. The debris that collects may require cleaning. The following equipment may require replacement: Filter elements, parts in air tools such as O-rings, and tubing.

If the equipment is dirty – then the inspector should tell the employee responsible to clean the equipment. If the equipment is cracked or damaged, the maintenance personnel should be informed so that they can determine the return on investment for either repairing or replacing the equipment.  Tracking the condition of your compressed air system is as important as conducting regular inspections.

Inspection List

“Treatment without prevention is simply unsustainable” – Bill Gates

“It is usually impossible to know when you have prevented an accident.” – Mokokoma Mokhonoana

Being proactive by inspecting your compressed air system regularly not only increases the life span of your equipment, but also your operation, maintenance, down-time, and replacement costs will decrease. Leaks divert up to 25 percent of your compressed air away from your system. Finally, it is an excellent source of information that is helpful in determining a return in investment for repairs.

Assessments could include an accurate Cubic Feet per Minute (CFM) scoring for objective measurement. Single stage air compressors may reach pressures of 150 PSI. A single stage pump has higher CFM rating than a two-stage pump since every cylinder compressing air during every rotation.

Here is a list of items to inspect on a daily, weekly, and monthly basis:

Daily

The following items need to checked most often:

• Listen for strange sounds
• Keep everything tight: accessories, nuts, bolts, anchors, and screws
• Check for leaks in the air inlet, receiver, delivery lines, coupling, filters, fittings, valves, and connectors.  
• Search for damage to external equipment or component parts
• Quality of pipes: Pipes that are clean, dry, and free of corrosion are great indicators of good quality tubing and hoses
• Wear and tear of equipment, especially piping. Check for damaged, aging, or cracks.
• Check for cracks in drive belts and coolers
• Aging disconnects for leaks
• Oil level on airline lubricators and replace oil regularly
• Compressed air enclosure temperature
• Operating temperature and pressure of the entire system
• Room ventilation temperature should be as cool as possible
• Clear and clean drain traps
• Look for decreases in:
  • Pressure
  • Dew point
  • Refrigerant pressure
• Check lubrication in the distribution system and valves
• Check air quality. It should be free of debris and dry
• Power supply to air compressor is working well
• Ensure that manual distribution condensate traps have not been left open
• Check accessories for wear, dirt, or leaks:
  • filters (oil and air),
  • separators (shims)
  • nozzles
  • pumps (air, vacuum)
  • fitted drive belts

Weekly

Dust and sludge corrode very quickly and increase leaking in compressed air equipment.  Keep the air in the system dry and filtered to reduce maintenance. It is recommended that you check the following weekly:

• Lines
• Gaskets
• Fittings
• Valves
• Clamps
• Connections
• Filters for dust, dirt, or sludge
• Tanks
• Condition of oil
• Compressor
• Check the coolant and refill it regularly since the coolant prevents your system from overheating and prolongs the life of your compressed air system.
• Use test buttons on electronic systems and manual bypass valve to ensure that all drain traps are working correctly

Monthly

The following items should be checked monthly:

• Examine your compressed air system system’s response to manufacturing requirements
• Calibrate sensors, controllers, and valves
• Access your factory’s true production level efficiency and determine areas of improvement
• Completeness of air compressor system assembly
• Equipment rotation
• Equipment identification, labeling and tagging
• Adequate working space for ventilation
• Control system
• Comparison to plans and drawings
• Safety devices
• Test the following for operation efficiency:
  • Air compressor
  • Air dryer
  • Water and oil separator (if applicable)
  • Pressure
  • Filter and traps
  • System test
  • Receiver system is stopping at the set maximum pressure

Most importantly, take notes and track your information so that you can identify trends and budget for future expenses such as repair and replacement of aging equipment. Information that is important to note includes: operating temperatures, pressure, flow, and levels.

After the Inspection

Regular inspections should be conducted by the same employee but if that is not possible track the personnel who did the inspection by recording the following information: Name, Designation, Contact Information, the Time and Date of the inspection with signature sign off. The inspection should be acknowledged by your safety liaison officer and manager. The approval of the inspection should be signed by the person responsible for inspection. Typically, the person responsible is the factory floor manager.

Nex Flow technical experts are happy to help you inspect, analyze, and recommend areas in your factory environment that could improve cost savings, reliability, and productivity.

Nex Flow compressed air accessories can complement and enhance your compressed air systems. Awareness of the best accessories (based on application) can save energy, extend the lifespan of equipment, and provide a safe environment for workers when using compressed air. This article describes tips that enhance the performance and prolongs the life of compress air accessories.

What are Examples of Compressed Air Accessories?

Compressed air accessories include filters (oil and water), separators (shims), valves, nozzles, tubing, hoses, etc. Nex Flow engineering experts are happy to provide advice when choosing the best compressed air accessories for your application. We are dedicated to reducing the cost of compressed air system operation and extending the life of your products.  All products come with a 5-year manufacturing warranty.

Prevent Leaks

Benjamin Franklin once said, “An ounce of prevention is worth a pound of cure.”  Be proactive by regularly checking for leaks in filters, fittings, valves, and connectors.  Leaks occur especially when your compressed air system is aging. Inspecting your entire system regularly prevents leaking air. Leaks can originate from lines, gaskets, fittings, valves, clamps and connections. They can divert an estimated 25 percent of your compressed air. Leak detectors can be helpful in identifying the issues before they become costly to repair. In addition, solenoid valves can be used to control the flow of liquid and gases.

Check the quality of pipes in your compressed air system. Simply using quality and replacing worn out pipes can save energy and maintenance costs. Pipes that are free of corrosion, clean, and dry are a good indication of quality piping.  If the air is not properly filtered, dust appears in the pipes which could lead to inlet filters becoming clogged, causing a decrease in pressure, and the chance of product contamination. If left unattended, wastes will accumulate, and these dust and sludge will corrode piping very quickly and exacerbate leakage. Properly dried and filtered air keeps your pipe system clean and reduces maintenance.

Inspect Equipment Regularly

Strange noises and excessive vibration are indications of problems. Learn to recognize issues as soon as problems occur.  Inspect the entire compressed air system regularly including accessories. Keep everything tight because otherwise screws, nuts, and bolts can all loosen. Tighten accessory that has become loose.  It is highly recommended to regularly inspect your system, understand and know the acceptable range of the gauges so you can flag if the system is abnormal. This knowledge can prevent major damage to equipment and prevent costly repair. Check the coolant and refill it regularly since the coolant prevents your system from overheating and prolongs the life of your compressed air system.

Cleaning

With the help of expert technicians with years of experience, develop a daily cleaning routine of your system and accessories. Remove filters and blow them clear of dust to extend the life of the pipes, filters, and nozzles. Dust and debris can collect in filters and if they clog, it will impact the effectiveness of your system. Other than dusts, filters should also be drained of any liquid they collect. Remember that any residue may dry and leave a film – this is especially hard to remove if it is an oil residue. So before putting the filters back in use – it is important the filters are properly drained and cleaned to prolong the lifespan of the product.

Seek out moisture in your entire system. Moisture can cause wear and tear on your accessories.  Condensation can deteriorate the health of your system and shortens the lifespan of equipment. Ensure that the air compressor is eliminating moisture as expected on a daily basis.  Furthermore, check drains and separators to ensure that no moisture is pooling.

Maintenance

It is highly recommended to follow the compressor maintenance schedule. Ignoring maintenance costs more because it leads to costly repair and replacement expenses.   It is critically important that the correct lubricant is used on tools and compressed air accessories to promote long life. Incorrect lubricant can damage internal parts. For blow-off or air conditioning systems, it is equally important not to use a lubricant since it could block the nozzle. In situations where the entire air system is lubricated, it is recommended that an oil removal filter is installed upstream.

A compressor runs more efficiently when properly maintained. Proper compressor maintenance cuts energy costs and prevents breakdowns.  Maintain oil change schedules and other timely scheduled maintenance on your compressors. Consult your air compressor supplier for advice regarding the most efficient method to run based on the application of use, especially if you own several compressor units.

Vortex tube cooling for cabinet enclosures is essential in very dirty or humid environments. The use of cabinets coolers not only keep the control panel clean but also keep maintenance costs to a minimum.  If the equipment become clogged and stops working, the cost of an enclosure is easily recovered compared to stopping work to repair sensitive parts on the control panel.

Pre-packaged Electronic Thermostat

Setting the temperature of when compressed air will be used, will extend the lifespan of your equipment. Thermostats control the temperature setting inside your control panel.  The compressed air equipment will only be used when necessary. Also, Nex Flow® Panel Coolers ensures a positive pressure to keep out atmospheric air in control panels.  A small amount of air flowing into the control panel is important to maintain a slightly positive pressure. Nex Flow also offers a special temperature-sensitive sticker that is put on the outside of a control panel as a qualitative indicator to show when a  panel is overheating. 

Proper Filtration Use

Using proper filters based on the application and changing filters regularly will prolong the life of your blow off products. Instead of using cartridge filters, where water and oil removal pose a high maintenance cost, it would be wise to use the following compressed air accessories for longer life:

Oil Removal Filters – an excellent choice for oil removal because it filters up to 0.3 microns.

Liquid Super Separator – removes 99.99% oil and water from a compressed air system. This filter addresses access water problems and extends the life of existing filters.

Use Stainless Steel Shims for longer life

Unlike other manufacturers – Nex Flow® only sells stainless steel shims because we understand that plastic shims will wear out quickly. When required, shim kits and individual sizes are available for spare parts, enlarge the gaps in existing products to increase flow/force, or to replace old shims if necessary.

Conclusion

Having keen knowledge of how your compressed air system works optimally only occurs when a regular maintenance and inspecting schedule is kept. Once you are aware of your compressed air system, issues. Loose or loud components, can be quickly replaced and maintained before expensive repairs are necessary.  Knowing the correct compressed air accessory for the application will save operation costs and extend the life of the equipment you have installed. Nex Flow is the company that is most qualified to help you select the most effective compressed air accessories for your application.

LOUDER DOES NOT MEAN MORE POWER

Have you ever heard someone said something along the lines of “well that’s definitely a powerful machine – just listen to how loud it is”. While this may be true some of the time it is not always the case.  When working with compressed air, having a well-designed machines and accessory that is equally powerful at a much lower noise level is always a plus. Here are some things to consider about noise.

Loud Noise Means Less Efficiency

Have you ever tried to concentrate with loud noise? It is much more difficult to think clearly with loud noise. But it’s not just personal efficiency that can be negatively affected, the efficiency of the device making the noise can also be jeopardized. For instance, the noise involved with compressed air blow-off can mean a leakage or an inefficient design. It is still prevalent to use open tubes and jets and drilled pipe for blowing compressed air in production applications to clean, cool and move products. However, the exhaust noise using these methods can exceed 90 dBA depending on the pressure used and the bulk of the noise generated by this method of blowing with compressed air is from the energy lost as it exits the tube or pipe. In other words, the energy is loss as noise and pressure drop because the flow and force from dilled pipes and open tubes are mostly turbulent.

Turbulent Flow can be characterized as having tiny whirlpool regions and it also increases the amount of air resistance which is useful for accelerating heat conduction and thermal mixing. However, it is not useful for blowing applications. Turbulent flow will produce a great deal more noise. For blowing with compressed air, whether for cooling or cleaning or drying, laminar air flow is preferred.

Laminar Flow is when the flow of a fluid (in this case, air) follows a smooth path, or paths which never interfere with one another. One result of laminar flow is that the velocity of the fluid is constant at any point in the fluid movement path.

Just how much can noise be reduced and how much energy saved using blow off products that produce a laminar flow? The answer is – quite dramatic. A laminar flow nozzle can reduce noise levels as much as 10 dBA and reduce energy consumption by 30% – 40%. Likewise, laminar flow air knives which is basically long, flat nozzles are used to replace drilled pipe for higher efficiency. Some designs are extremely quiet and can reduce exhaust air noise to as low as 69 dBA.

High Noise Level is a Hazard

Of the roughly 40 million Americans suffering from hearing loss, 10 million can be attributed to noise-induced hearing loss (NIHL). NIHL can be caused by a one-time exposure to loud sound as well as by repeated exposure to sounds at various loudness levels over an extended period of time.

Sound pressure is measured in decibels (dB). The average person can hear sounds down to about 0 dB, the level of rustling leaves. A handful of people with very good hearing can hear sounds down to -15 dB. On the other end of the gauge, a sound that reaches 85 dB or stronger can cause permanent damage to your hearing even if exposed for a very short time. The timespan you listen to a sound affects how much damage it can cause. The quieter the sound, the longer you can listen to it safely. A very quiet sound will not cause damage even if you listen to it for a very long time. However, a sound that reaches 85 dB can cause enough damage to induce permanent hearing loss. Here are some common sounds.

• A typical conversation occurs at 60 dB – not enough to cause damage.
• A bulldozer that is only idling (not actively bulldozing) is loud enough at 85 dB – after only 8 hours it can cause permanent ear damage.
• When listening to music – a stock earphones at maximum volume can generate sounds reaching a level of over 100 dBA. Loud enough to begin causing permanent damage after just 15 minutes a day!
• A clap of thunder from a nearby storm (120 dB) or a gunshot (140-190 dB, depending on weapon), can both cause immediate damage.

It is estimated that as many as 30 million Americans are exposed to potentially harmful sounds at work. Even outside of work, many people participate in recreational activities that exposes them to harmful noise (i.e. musical concerts, use of power tools, etc.).

Designing the Future of Air Blow Off Technology

Nex Flow^® Air Products Corp. continually perform and fund research to constantly improve the efficiency and safety of compressed air accessories. With this approach, we are able to offer noise reduction for compressed air technologies that are equally or more efficient than competitive units.

Air Nozzles
Our Air Nozzles are engineered to reduce noise by 10 dBA over open pipe, tube or jets and maximize laminar flow to increase force/compressed air consumed.

One of the oldest styles of air saving, noise reducing air nozzles are of a cone shaped design. But if you put every single design next to one another both energy saving and noise reduction will vary greatly because many times the aerodynamic design is neglected. Having the nozzle outside appearance as a cone shape in not enough. There are many other (proprietary) factors to consider to truly minimize turbulence and maximize laminar flow. The cone shaped designs are still the optimum style to use for maximizing total volume of flow produced per quantity of compressed air consumed and is especially ideal for cooling applications. Where cost is a factor, this model is ideal.

The Air Mag is another one of our engineered nozzle with patented design. The bullet shaped design trumps the cone shaped design for producing the highest force/quantity of compressed air consumed. The patented design allows the Air Mag to provide the furthest distance for laminar flow compared to competitive units. Other bullet shaped nozzles need to be close to the target as turbulent flow begins to occur after only a short distance from the nozzle. Our unique design helps significantly extend the range of the laminar flow. Due to increased complexity and manufacturing processes, they are more costly than the cone shaped designs. However, they are the best option for when force produced is an important factor.

Air Knives
When replacing drilled pipe with holes, the Nex Flow Silent X-stream Air Blade air knife lives up to its name. At 80 PSIG the unit is runs on just 69 dBA exhaust noise and uses the same air consumption as if running competitive units at 60PSIG. Extremely popular as they often replace competitive units in the field because of the design and quality of manufacture.

Other blow off products we offer include air flow amplifiers, air jets, and many more. Our accessories are used not only for blow off and cooling applications but can also be used for conveying, cleaning and to control static electricity.

The next time you hear a loud sound when using compressed air anywhere in the production line, don’t forget to check and see what is making that noise. Loud noise is a health hazard and is often wasted energy. So, if the source of the noise is coming from an open tube, open pipe or a drilled pipe of any sort, chances are, you can reduce this noise very quickly and even reduce energy and get better performance by using low cost products from Nex Flow^®.

Pressure and Volume amplifier differences

Differences and Application: Pressure Amplifier VS Volume Amplifier

Sometimes when promoting our air amplifiers there is confusion as to whether it is an air “flow” amplifier or an air “pressure” amplifier.

Pressure Amplifiers

Air pressure amplifiers are also known as air boosters and air intensifiers and are used for increasing or boosting existing plant air pressures. Each pressure amplifier comprises a spool valve that acts as a 4-way directional control valve. The single acting compressed air boosters displace air once per full cycle.   Regular plant air, normally at a range of 80 psig to 100 psig (5.5 bar to 6 bar) is supplied to this spool valve, which automatically cycles back and forth. The plant air fed into the spool valve is alternately directed, as the spool cycles to a main air drive piston in the air drive cylinder. This makes the piston cycle back and forth in the pressure multiplier.

The unit also has a high pressure section where the air to be pressurized is supplied. The air flows into the booster’s pressure chamber on the suction stroke through inlet check valves. It is then compressed out of the chamber on the discharge stroke through the outlet check valve. The reciprocating movement of the air drive section, connected directly to the high pressure section, creates a positive displacement of air through the inlet and outlet check valve.

Single and double acting high pressure booster models are available on the market. The single acting compressed air boosters displace air once per full cycle. The double acting high pressure air booster will displace air at every stroke, or twice per cycle, providing higher and more constant flows. Depending on the application pressures as high as 5000 psig can be produced.

These pneumatic air pressure amplifiers can sometimes be installed in different positions. All connections to the pressure amplifier must be equal to or greater than the inlet and outlet connection ports to prevent starving of the booster.

Nex Flow Air Products Corp. does NOT supply air pressure amplifiers.  They supply air flow amplifiers.

Flow Amplifiers

Rather than being a system of vessels, valves and cylinders, air flow amplifiers are an assembled series of parts that normally work on the coanda effect, although they can also utilize a venturi effect if less air flow amplification is required. The air flow amplifiers that utilize the coanda effect are both energy savers and noise reducers because they basically convert pressure “drop” and “noise” losses into flow.  These systems are all based on aerodynamic shape to minimize losses and can “amplify” flow as much as 16 times inlet air or more depending on the size of the unit. The larger the unit assembly, the greater the air flow “amplification” or “air movement”.  Air flow amplifiers are sometimes called “air movers” because they can move large volumes of air or gas.  However, while they can move a large volume of air or gas, the vacuum produced is less.  If a larger vacuum is required then the venture effect is used.  In this case the shape and assembly does not use the coanda effect bur relies on a different means to entrain air or gas.  With this system you obtain a much higher vacuum but air flow amplification is limited to 5 or 6 times the input air volume.

Nex Flow manufactures both a coanda and a venturi version for air flow amplification. The coanda unit is available in two versions: the fixed X-stream Air Amplifiers work on the coanda effect and the compressed air exit gaps are controlled using stainless steel shims.  This gap can be changed by adding shims to open the gap for more air flow and therefore can “move” proportionately more volume. An adjustable version is available so you can “set” the gap to control the amount of compressed air used.

The venturi version from Nex Flow is called a Ring Vac. The units are primarily used for conveying materials as vacuum is more important for these applications. This device consists of a plenum “generator” with holes to discharge the compressed air into the direction if flow. This creates a vacuum behind the flow of air to entrain the atmospheric air. Its construction allows it to make the higher vacuum. A special XSPC version is available, which has the ring of air for the compressed air angled toward the direction of flow around the inside wall of the unit. This design is used when the material conveyed could possibly clog the Ring Vac design.

Pressure Amplifier Applications:

In Automotive manufacturing, air pressure amplifiers are used to provide higher air pressures for use with Robotics in such areas as Paint Booths, even for heavy blow off and cleaning as in welding spots, and for charging air cushions on presses on stamping presses in the body plants. They also provide assistance in procedures such as punching, riveting, and trimming with extra pressure. Other manufacturing and testing applications that have benefitted from Air Pressure Amplifiers are the manufacture and assembly of Brake pads, pressure testing of steering hoses, radiators and radiator hoses, air conditioning condensers, cooling and refrigerant tubing and systems. Air Pressure Amplifiers are also used in automotive repair and tire shops where higher air pressures may be required. Other applications within the automotive industry include the manufacture and testing of Airbags.

These pressure boosters are also used in the oil and gas industry for boosting gas pressures for pressure testing of vessels. Centrifugal compressors equipped with dry gas seals use the process gas as a seal gas. During normal operation, the compression of the gas generates heat, pressure and flow to the seal, preventing contamination and condensation. During start up or shut down, however, these conditions are not met and the seal is at risk of contamination specifically from heavy condensate.  Air Pressure Amplifiers are used as dry seal gas boosters to ensure that seals are pressurized with dry gas during start up and shut down.

Other common applications for Air Pressure Amplifiers in general manufacturing are as follows:

• Leak detection
• Pressure testing
• Increase pressure to air drying
• Increase pressure to nitrogen generators
• High pressure tire filling
• Increase force from pneumatic valve actuators
• Increase force from pneumatic cylinders
• Increase force from pneumatic presses
• Maintain pressure on inkjet printers for labeling
• Increase holding power of pneumatic chucks
• Increase pressure for products packaging
• Increase force for pigging paint and syrup lines
• Increase pressure on sandblasting equipment
• Increase force of pneumatic springs
• Increase force of pneumatic lift tables
• Increase force of pneumatic shears
• Railroad brake testing
• Unloading railroad cars using pressure
• Shield gas for plasma and laser cutters
• Increase pressure from pneumatic gas boosters
• Increase pressure from pneumatic piston pumps
• Increase pressure from pneumatic diaphragm pumps
• Increase force from ejection pins on plastic molds
• Blow Molding

FEATURED PRODUCTS

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Flow Amplifier Application:

Air Flow Amplifiers or Air Movers like the fixed and Adjustable Air Amplifiers are much simpler devices with lower costs. For Coanda type units, applications include:

• Venting welding smoke
• Conveying light materials
• Trim Removal in paper, film and foil processes if material is light and/or distances are short
• Drying of machine parts
• Cooling of Parts
• Cleaning of machined parts
• To Isothermalize or re-distribute heat in molds and ovens
• Ventilate tanks and other confined areas
• Dust collection
• Exhaust tank fumes

In these applications they are superior to using other devices like fans because they are compact, portable and lightweight.  They have no moving parts, no electricity, no maintenance, are easily ducted and simple in design.  Unlike fans they can be instant on and off and you can vary the force and vacuum.

Cooling of parts with Air Flow Amplifiers is especially advantageous over fans because there is no heat generated and the high velocity laminar flow cuts through the boundary layer on a hot part to remove the heat.  They can cool 10% faster that a fan to be able to increase throughput and with a much smaller footprint, with no maintenance. Cooling castings is a major application for air flow amplifiers using the coanda effect.

Venturi units like the Nex Flow Ring Vacs and XSPC units are used where vacuum is more important than the volume amplified.

• Hopper loading of plastic resin, caps, small parts
• Conveying of material
• Trim removal and waste in paper, film and foil for a wide range of weight and distances
• Transferring parts
• Chip Removal
• Filling Operations
• Tensioning of fiber

The units are compact, with no moving parts, simple in design with high throughput because of higher vacuum.

And of course, Air Flow Amplifiers of both types are low in cost, easy to maintain and last for years.

Compressed Air: 5 Associated Injuries and How to Stay Safe

While compressed air is relatively safe compared to many other sources of power, especially electricity, there are still safety issues that need to be considered with using compressed air. Here Nex Flow shares 5 injuries associated with compressed air operations and how to steer clear of them.

1. The Eyes

The most common injury from the use of compressed air is to the eyes. Compressed air is used by most industries and is often used to blow off and clean work places of dirt and debris. A prominent cause of eye injury is when chips and particles bounce back towards the operator when blowing off or working. This is often not stressed enough, but it can be a huge safety risk as the eyes are one vital way for us to sense the environment. Even the smallest of particle has the potential to cause a large injury, especially if correct safety equipment is not readily accessible. As little as 12 pounds of compressed air pressure can blow an eye out of its socket.

According to the United States Occupational Safety and Health Administration (OSHA), up to 90 percent of eye injuries can be prevented with correct safety equipment. When flying chips and particles is part of the work environment, wear safety glasses with side protections. These help to prevent back bouncing particles from getting in behind the safety glasses and cause harm.

Three important things to think about to decrease the risk of eye injuries:

1. Work preventively by understanding the nature of the work assigned and minimize the risk of harm

1. Identify and eliminate potential risks before diving straight to work. Remember that work screens and other guarding equipment can be used to limit risk area.

3. Use proper safety equipment that protects the eyes.

To work without safety in mind in an environment where eye injuries can occur can be very expensive. The annual cost of eye in juries is estimated to be over $300 million per year. To increase safety, and extra protection when blowing off, air guns with safety shields can be used to minimize the risk of chips and particle that can be blown behind safety glasses and cause potential injury.

2. The Ears

Compressed air noise can cause damage to the ears. Compressed air exhaust noise can be quite noisy when used for blow off or cooling. Blowing with compressed air can result in elevated noise levels that can be harmful to both the operator as well as the surrounding persons. Both short and repeated blowing operations can be harmful and result in hearing damage and tinnitus. The damage can appear gradually, and it can be difficult to determine when and how the hearing problems developed. OSHA’s regulations also affect the approved noise level of a workplace. Open jets and pipe can produce noise levels as high as 90 dBA or more which is very dangerous to hearing even with short term exposure. Learn more about noise levels here. In any factory environment, there are certainly many other sources of noise from moving machinery, grinding of gears, the squeaking and clanging of chains, and banging of parts. Damage from compressed air noise can have serious and damaging effect on your hearing due to high noise exhaust levels. Fortunately compressed air exhaust noise can be addressed by the use of exhaust mufflers on devices such as air cylinders and the use of engineered air nozzles, compressed air amplifiers, and air knives to reduce the noise levels significantly.

3. The Skin and Body

Skin and body damage can also occur from flying debris when using compressed air for blow off or cooling. Blowing to cool a hot part can cause a chip or hot dirt particle to become loose and possibly fly towards and burn your hands and arms. Even small particles can bounce back and at high enough velocity can embed into the skin and cause infection later on, even if not felt immediately. Again not only is the use of eye shields important but it is equally important to wear protective clothing when handling compressed air in a high risk environment. Compressed air accidentally blown into the mouth can rupture the lungs, stomach or intestines. Even with a layer of clothing, compressed air can enter through the navel so be cautious and pay attention to your surroundings when in an industrial environment. It also helps to know and abide by compressed air safety standards.

FEATURED PRODUCTS

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4. The Bloodstream

A very serious situation occurs when compressed air enters the bloodstream – an aeroembolism. This can happen if the operator is blowing compressed air on themselves or someone else. If the pressure becomes too great or the compressed air is blown directly against the body, the compressed air can get underneath the skin and into the bloodstream.

Compressed air is a concentrated stream of air at high pressure and high speed that can cause serious injury to the operator and the people around him. First, compressed air in itself is a serious hazard. It has been known for compressed air to enter the blood stream through a break in the skin or through a body opening. An air bubble in the blood stream is known medically as an embolism, a dangerous medical condition in which a blood vessel is blocked, in this case, by an air bubble.

An embolism of an artery can cause coma, paralysis or death depending upon its size, duration and location. While air embolisms are usually associated with incorrect scuba-diving procedures, they are possible with compressed air due to high pressures. This may all seem to be improbable, but the consequences of even a small quantity of air or other gas in the blood can quickly be fatal so it needs to be taken seriously. Unfortunately, horseplay has been a cause of some serious workplace accidents caused by individuals not aware of the hazards of compressed air and/or proper work procedures. If an air pocket reaches the heart, it causes symptoms similar to a heart attack. Upon reaching the brain, pockets of air may lead to a stroke. Therefore to stay safe, do not use pressurized air to blow on yourself and other personnel, and avoid horseplay when working with compressed air.

5. Faulty Equipment

Another danger to be aware of when using compressed air is with hoses and quick disconnects. Leaking or damaged hose or connectors can be quite dangerous as they could break. Under pressure broken hoses or hoses that come loose from the system because of failed connectors can whip around and cause serious injury. If people are working with old or frayed hoses, air may leak out causing a pressure drop. This lack of pressure can cause machines to malfunction and other problems. If the hose is damaged and then pressurized it could cause injury when it ‘explodes’ outward. This sudden release of the pressure can cause a machine to engage or disengage, resulting in injuries to the operator and bystanders.

To stay safe, check the hoses regularly and never – of course – use frayed, damaged or deteriorated hoses. Worn connectors and hoses should be replaced immediately. Store hoses safely, away from heat and sunlight to prolong the product lifetime. Hoses are best stored on a hose reel for longer life, and to avoid tripping hazards.

Compressed air is still one of the safest and friendly utility to use with many advantages.  But while relatively safe, certain precautions as listed above are still necessary so you can safely enjoy the benefits of compressed air.

How do mufflers work and how often should you change your muffler

Compressed air exhaust can be quite noisy. Nex Flow’s air amplification technology is used to reduce the noise in all sorts of blow off, cooling and drying applications by converting the energy wasted as noise and pressure drop into useful flow and force.

But there are other applications where sound reduction is important as well.

Reclassifying Mufflers

Ports on cylinders, valves and other air operated equipment for exhaust noise exhaust air and this exhausting air can be noisy. Normally mufflers are added to these ports to reduce the exhaust noise.  Different units exist to reduce this noise – sintered bronze or sintered plastic mufflers are common. These mufflers should have minimal back pressure so it does not negatively affect the operation of the cylinder, valve or part. They are sized to be able to pass through a certain amount of exhaust air. The sintered mesh design attenuates the exhaust air noise to reduce the noise level as the air leaves the unit. A visual check can determine if the muffler needs replacement but usually a replacement schedule is set up depending on the history of the plant operation.

Reclassifying mufflers offer greater noise reduction than sintered bronze or sintered plastic units (up to 35 dBA noise reduction). They are also designed to eliminate the oil mist that is often in compressed air used by cylinders and valves for lubrication. The exhaust air leaving cylinders and valves can pollute the working environment with oil mist that can adversely impact the health of the factory personnel. In the USA, OSHA Standard 29 CFR 1910.10 states that a factory employee’s cumulative exposure to oil mist must not exceed 4.32 PPM (parts per million) in any given eight hour shift in a 40 hour week.  Similar standards limiting oil mist exposure exists in other countries.

The reclassifying muffler supplied by Nex Flow Air Products Corp. is a patented wrap design for the removable filter element that separates and removes the oil from the exhausted air existing the cylinder, valve or other machine part so that no oil is released into the factory environment. For example, if the exhaust air contains 50 PPM of oil mist at 100 psig, the reclassifying muffler will reduce the oil mist entering the plant atmosphere to 0.015 PPM. The reclassifying muffler incorporates a reservoir to collect the removed oil which can be drained by attaching a ¼” drain line. Then the recovered oil can be properly disposed of. Replacement filter elements should be changed on a scheduled maintenance program depending on plant history.

As with other types of mufflers describe earlier, the reclassifying muffler is designed to pass a certain volume of exhaust air with minimal back pressure to avoid interfering with the operation of the cylinder, valve or machine part.  When used on cylinders, refer to this chart for easy selection based on the bore and stroke of a cylinder.

Noise is also generated when using venturi systems like the Ring Vac. Here the muffling has to be accomplished using vacuum hose attached at “each end” of the unit. Any muffling device used in line will cause too much back pressure and make the use of the product ineffective. However, the hose itself can be quite effective in reducing the noise generated by the action of the product.

One compressed air technology that can be quite noisy used alone is the vortex tube. When using vortex tubes, the air must be properly filtered to avoid oil and dirt building up inside the unit so some effective means of oil mist removal is required in their muffling.

A vortex tube takes compressed air and literally splits it into a hot and a cold stream. The hot stream is normally exhausted at one end (the hot end exhaust) into the atmosphere, and the cold stream is used for spot cooling. The exhaust air creates noise at both the hot end and the cold end, but the majority of the noise is at the cold end. Vortex tubes are sold separately and in packaged versions for a variety of applications – for tool cooling, for camera cooling and for cabinet cooling as major applications. In the packaged versions they typically utilize a sintered muffler at the hot end to reduce the noise from the hot end exhaust, similar to the sintered mufflers commonly used for cylinders and valves. The cold end typically uses a specially made muffler with sound absorbing material inside to absorb the noise generated by the exhausted cold air. This cold air does not go through this sound absorbing material (like the hot air does in the sintered material). Instead, the sound absorbing material is wrapped around the inside wall of a cylindrical piece attached to the cold end of the vortex tube. This is because the back pressure would be too great and would negatively affect the cold temperature if the sintered model is used for muffling. A proper cold end muffler also has a metal piece to hold the sound proofing material in place (the metallic piece normally has large holes or gaps to keep sound proofing materials effective). Most companies use plastic as the sound muting material, however Nex Flow uses special natural sound proofing material that is also fire resistant and is biodegradable. Although slightly more expensive – this makes our Hot and Cold End Muffler better at sound proofing and is far more environmentally friendly than plastic units.

When vortex tubes are purchased separately, a hot end muffler is available to be purchased separately (a sintered type) and the cold end muffler used in the packaged versions can also be purchased separately.

If the compressed air if properly filtered in advance, these hot and cold end mufflers should not need replacement.  But it is wise to check annually for dirt or oil buildup on the mufflers or anywhere on the vortex tube unit to assess if replacement or cleaning is necessary and then check the filter system and repair or improve as necessary.

To reduce noise further either a flexible hose or plane plastic tubing can be used to convey the air to the point of use or to be distributed for cooling control panels.

Exhaust compressed air can be noisy, so it can either addressed by exhaust “design” as is done with air amplifying products or with mufflers of the type mentioned herein depending on the product.

How is Compressed Air Used to Convey Products?

Compressed air systems are used to convey all types of solids, plastics materials, metal pieces, waste, chip, and trim removal in a manufacturing environment. Internal air conveyor describes items that are moved in the same pipe as the air moving the items. This type of conveyor is used in packaging industries. Since the pressure lessens in the pipe with increased distance, internal air conveyors are limited to lengths of about 100 ft. (30 meters). Sometimes these conveyor systems are referred to as pneumatic conveyors.


In general, pneumatic conveyors easily move items at faster speeds than other types of conveyors. They are also ideal for moving scrap where conventional conveyors would become quickly clogged or contaminated with debris. The inside diameter is recommended to be roughly twice the diameter of the part/material being moved to help prevent clogging. Air conveyors are also useful when transporting sharp or abrasive materials. Metal scrap and recycling centers are perfect places to utilize air operate conveyor because long ribbons of razor-sharp metal can easily snag other types of conveying equipment.

Air Conveyor is most commonly used for moving lightweight objects such as empty containers, boxes, and trays at speeds often exceeding 1,000 fpm, but they are not limited to lightweight materials. Different air operated conveyor systems are designed to convey different types of products and perform various specific tasks. Other common applications include hopper loading (resin in the plastic industry, bottle caps in bottling, etc.), transferring parts from one location to another, tensioning fiber, in filling operations and vent gas in some cases. The gaseous elements are conveyed by the vacuum action and sometimes vented to the atmosphere. Air conveyors are also well suited for handling corrosive or high temperature gas because no electricity is involved, and they can be supplied in appropriate materials. This means that the unit can be customized to meet safety standards and are virtually maintenance free.

How it works?

The Ring Vac and XSPC are air operated conveyor units offered by Nex Flow which uses the Venturi effect. The effect is a version of the Bernoulli’s principle which essentially allows it to increase the speed of the flow to maximize conveying efficiency. Refer to this article to learn more about the Venturi Effect.

The air operated conveyor uses a series of holes to blow compressed air in one direction creating a vacuum to draw in and move the gas. The number of holes in the system is dependent on the size of the unit, which pulls the air behind the unit creating a vacuum, drawing in any gasses and then pushes them away. It is an ideal solution for moving gas through longer distances aided by the extra vacuum.

Other than being used to convey products and goods, air conveyors are sometimes used for venting. Typically an air amplifiers is used for venting purposes, but the pneumatic conveyor do offer some benefits especially if the gas is contaminated or that the vented materials could potentially deposit materials on the Coandă angles of the amplifier. Over time, these deposits could stop the amplifier from venting. For air operated conveyors, the compressed air enters through a different vent, so there is less opportunity for dirt deposits if the gas is contaminated. The air operated conveyor produces a higher vacuum but does not move as much air volume as an air amplifier. The Venturi system is a simple unit to manufacture and is lower in cost. It requires less air pressure to operate and is available in aluminum, stainless steel (standard), with special units made in Teflon, and other plastics and metals.

Unlike an air flow amplifier, the Ring Vac Venturi system moves less volume but creates a higher vacuum. Therefore, this system is ideal for venting gas because it is manufactured at a lower cost and it operates at a lower air pressure thereby saving energy. Do note that, the length of the distances transported vertically and horizontally depend heavily on the types of material being conveyed.

Advantages for air operated transporter systems

Significant advantages of using of these systems are their compact size, instant response time, and portability. They are also clean, quick and efficient machines that are designed to transport or vent a wide variety of lightweight products, raw materials, or fumes from one place to another. Air conveyors typically have minimal moving parts and no pockets to collect debris and water, which makes them safe and easy to clean and maintain. Their flow rate is easily controlled with a pressure regulator.

Overall, the air operated conveyor systems are made so they are easy to use, lightweight, maintenance free and does not use electricity. The systems are ideal for both continuous and intermittent use. They are designed to use compressed air efficiently across the entire length and over long distances.

There are several advantages of using Nex Flow air operated conveyor systems (either the Ric Vac or the XSPC conveyors).

The Ring Vacs are primarily used for conveying materials for applications where a vacuum force is beneficial. The Ring Vac moves objects over long distances at high speeds and has an on/off switch to enhance safety. It uses compressed air, not electricity, so there is no explosion hazard. The Nex Flow Ring Vacs are made of anodized aluminum. For high temperature and corrosive applications, regular and high temperature stainless steel are available. When moving food and pharmaceutical products, 316L Stainless Steel pneumatic conveyors are available. Clamp and threaded versions are available so you can simply clamp a standard hose to each end of the Ring-Vac® to start moving things with compressed air.

• Anodized aluminum for most applications – clamp on and threaded versions
• Extra Powerful hard anodized aluminum – clamp on and threaded versions
• Stainless Steel – clamp on and threaded versions for corrosive and high temperature environments
• 316L Stainless Steel – clamp on, threaded, and sanitary flanged versions for food, pharmaceutical and high temperature and corrosive environments.

Similarly, XSPC conveyors are compact, easy to use, portable, and ideal especially for intermittent use in material transfer. It uses compressed air to create a powerful moving force. The inside of the XSPC conveyor is straight and smooth to prevent clogging. The flow is controlled by a regulator making it perfect for non-continuous use and like the Ring Vac pneumatic conveyor – you can simply clamp a hose to each end to start enjoying the benefits of this efficient pneumatic transporter.

Everything about Bypass System for Control Panels

The Nex Flow Panel Cooler is a vortex tube operated air conditioning system used to cool electrical and electronic control cabinets. They have many advantages such as simplicity in installation, near zero maintenance, no condensate and more. But one major advantage for control cabinets in harsh environments is that when operating they keep control cabinets at a slightly positive pressure, therefore keeping out the factory atmosphere. Panel Coolers are utilized especially in environments that are very dirty, dusty, hot and moist, or corrosive. This ability to keep the control panels at a slightly positive pressure becomes very important. However, this is only the case while the Panel Cooler is actually operating.

On-off control

One of the ways to minimize compressed air use with a Panel Cooler or any vortex cooling system is to have some sort of an on-off control system. One method is to use a thermostat coupled with a solenoid valve to turn the compressed air on when the cooling is needed, or turn the air off when it is not required. However, when the Panel Cooler is off, it no longer keeps the control panel at that slight positive pressure. It is at this point where the factory environment can encroach into the control cabinet and possible to have a negative impact on the internal components.

Single VS Multiple Panel Coolers

If there are two or more Panel Coolers on a control cabinet, normally one runs continually and the other one (or ones(s)) cycle on and off as required for cooling. That is enough to keep the control panel, even if very large, at the slightly positive pressure enough to keep out an unfriendly environment. But when only one Panel Cooler is used then some creativity is needed.

One of the tricks of the trade in factories such as highly humid bottling facilities, even with standard air conditioners, is to take a small compressed air line and pipe a very small amount of compressed air constantly into the cabinet to keep out the humidity that could harm the controls. A typical Standard air conditioners go on and off, so the humidity needs to be addressed. Similarly in very corrosive and dirty environments, a tiny amount of compressed air piped into the panel solves the potential expensive repair of the internal parts of an electrical or electronic enclosure.

So what are the options when using a single Panel Cooler? One vortex cooler supplier uses a thermostat and solenoid package for on-off control but they drill a small hole into the solenoid valve so that in the “off” position, a small amount of compressed air continues to flow through the cooling unit.  There is not enough flow to effectively cool in the off position but enough flow to keep the cabinet at a higher pressure than the environment.

There are two disadvantages with this method.  

First, it may not be legal in some jurisdictions because drilling a hole in the solenoid valve may take away its electrical approval rating. This may result in all sorts of problems from insurance coverage to legal should something go wrong.  

Second, there is no control over how much of this air can go into the cabinet. For very large cabinets, it may not be enough air to make any difference in pressure, and for small cabinets there may be too much air flow that it wastes energy.

Overcoming the disadvantages

To overcome the above disadvantages – Nex Flow has designed a special by-pass system.

The by-pass system works with all panel coolers both Nex Flow and non-Nex Flow units. It consists of a control valve that is connected between the compressed air supply (after filtration) at the inlet to the solenoid valve that controls the on-off operation of the vortex cooling system.  There is a small tube emanating from the control valve that is connected to a three-way fitting that connects to the outlet of the solenoid valve. One inlet is for the tube, a second inlet connects to the outlet of the solenoid, and the other connection goes to the line that takes the compressed air to the cooling unit.

This overcomes both the previous disadvantages mentioned. The solenoid valve is not tampered with so no electrical approvals are jeopardized and eliminating any potential insurance or legal issues.

The control valve on the inlet side of the solenoid valve has a small knob to set the amount of by-pass compressed air used. It can be set to a very small flow rate for small control panels to save energy and a higher flow rate for larger control panels to insure there is enough air flow to maintain a higher pressure than the environment. Control remains completely in the hands of factory personnel and not with a tampered solenoid valve.

The Panel Cooler by-pass system is also made of all 316 stainless steel so it can be used in all types of environments and with all ranges of Panel Coolers offered by Nex Flow (and their competitors) including NEMA 4X (IP 66) environments. The system is simple to install, easy to use and versatile.

In relatively benign factory environments, a by-pass system may not be necessary. Furthermore, if the Panel Coolers operate continuously they are obviously not required. To determine if having a by-pass system would be beneficial, you simply have to access the plant environment. In corrosive atmospheres or highly humid atmospheres the benefit is quite clear cut. However, regardless of the environment, when used, they have been proven as an effective way to keep the internals of a control clean and dry.

If there is more than one Panel Cooler, as mentioned earlier, normally one is always operating.  However, if the plant atmosphere is really harsh, it might still be useful to have a By-Pass System on at least one cooling unit assuming the control panel is completely shut down during a plant shutdown.

As with all Panel Cooler installations, it is important to have proper filtration to remove any loose water or oil to keep the system clean and dry.  

Compressed air is used in many industrial cleaning applications. This ranges from blowing off a workstation to cleaning blind holes and even using the Hand Vac to vacuum hard to reach areas. In this article – Nex Flow discusses some of these options and the advantages of different systems.

There are three manual cleaning devices offered by Nex Flow, each with their own uses:

1. Safety Air Blow Guns (4 versions)
2. X-Stream Hand Vac
3. Blind Hole Cleaning System

Safety Air Blow Guns

Safety air guns are used for all kinds of cleaning applications although in some jurisdictions they are not allowed to be used for personnel cleaning of clothing by law, even if they are safety guns.  This is understandable as compressed air, although very safe in many aspects, can be dangerous if used irresponsibly.

There are four different Safety Air Blow Guns offered by Nex Flow (listed below), all meant to be used in production applications. The advantages of each air gun is their ergonometric design and all of them incorporate safety air nozzles which effectively reduce noise and energy use while in compliance with OSHA safety standards for dead end pressure.

1. Easy Grip Safety Air Gun
2. Easy Grip Light Safety Air Gun
3. Hand Comfort Button Gun
4. Heavy Duty Safety Air Gun

The Easy Grip Light Air Gun incorporates the Nex Flow 6 mm Air Mag nozzle and is used primarily for blow off applications on small parts and to blow off and clean small spots.

The Standard Easy Grip Air Gun is larger with a ¼” outlet for larger spot blowing applications and is compatible with a variety of Nex Flow safety nozzles, including the ¼” Air Mag nozzle and even the Air Edger flat nozzle. It also comes with optional extensions of various lengths for accessing hard to reach areas for blow off and cleaning.

Our Hand Comfort Button Gun is designed for those that prefer a button style rather than a trigger style gun for small blow off applications. As with the Easy Grip “Light” it is used for smaller blow off applications. The nozzles used are limited to 1/8” connections or smaller. The same 6 mm Air Mag nozzle used on the Easy Grip Light can be adapted to the Hand Comfort Gun. Whether you use the Easy Grip Light or Hand Comfort Gun really depends as much on preference of the user as the particular application. For hard to reach applications where extensions can be of help, the Easy Grip Safety Air Gun would be used.  

For very heavy duty cleaning applications a much larger capacity Safety Air Gun is necessary. Nex Flow is one of the few manufacturers of such Safety Air Guns. The Heavy Duty Safety Air Gun has a ½” outlet and is used with the ½” Air Mag nozzle. These guns provide a powerful force necessary to clean large machinery such as those found in steel plants, and paper mills and other large manufacturing environments. As with the Easy Grip Safety Air Guns, these Heavy Duty Safety Air Guns can also be provided with extensions to get closer to and into hard to access areas such as moving paper in a paper mill or blowing off waste metal from metalworking products. Since these air guns are heavier and provide more force, the air gun should be heavily ergonometric in design for comfortable use. Any extensions should have a rubber grip to hold the system securely when being used. Such air guns are never to be meant for personnel cleaning or light machine cleaning since they provide much more force than needed in such lighter duty applications.

X-Stream Hand Vac

The X-stream Hand Vac is an interesting device in that it is both a blow gun and a vacuum gun. As with Nex Flow air nozzles, the X-stream Hand Vac meets OSHA pressure safety requirements. The system uses a built in Venturi generator inside which can be reversed so that in one direction it acts as a blow gun and in the other as a vacuum gun. This gives it the flexibility of use as an option for cleaning both clothing and machinery by using vacuum to clean up dust and dirt. The unit is lightweight, portable and versatile. Various attachments come with the unit which include extensions to extend the reach for both blow off and suction, and a soft bristle brush that is attached directly to the unit or to the extension which makes for easy cleaning in vacuum mode.

When used in vacuum mode, the dust collected can be conveyed by a hose that is supplied and attached to the opposite end of the gun, into a container. As an option, the hose can be replaced with a collection bag connected to the opposite end of the air gun. The hose and collection bag along with brush attachment and extensions are supplied along with a clamp to hold onto the unit in the all-purpose Hand Vac kit. In addition, there is a skimmer attachment used with the extensions for light vacuuming.

As a blow gun, the unit has a wide area for blow off as opposed to a point so it is easier and faster to use to clean larger areas especially. The outlet diameter is 1-1/4” (32 mm). The unit is also energy saving in that it amplifies the air flow by 12 times the air consumption rate. Hence apart from blowing and cleaning surfaces, the amplified flow is ideal to dry surfaces quickly because of the wide surface area covered.

Other than blowing, cleaning, drying and vacuuming, the X-stream Hand Vac can be used for conveying materials. Transferring material over a long distance is possible by using the unit in vacuum mode with the smooth interior vacuum hose supplied. Transferring material up to ten feet (3 meters) is easily done by placing the Hand Vac (in vacuum mode) into the container with the material to be transferred and the hose end into the container at the desired location.   

Here are some applications for the Hand Vac:

• Vacuum shavings off machinery
• Vacuum absorbent material
• Vacuum spills off the floor or on machines
• Transfer small parts from one area to another
• Transfer trim material
• Blow off chips and scrap from machinery
• Blow off water, coolant and other liquids off parts and machinery

While it can act as both a vacuum and a blow gun, it may not be as powerful as necessary and sometimes too big for a blow off application. Hence there is still a need for safety air guns. Yet, the X-Stream Hand Vac fills an important gap that safety air guns alone cannot achieve due to its unique design and flexibility in use.

Blind Hold Cleaning System

The Blind Hole Cleaning System came about primarily for safety reasons. When blowing dirt and debris from deep holes, this material can be scattered around making a mess and can also be dangerous as it can get into your eyes and sharp pieces can even cut the skin. There have been some versions where units like the X-Stream Hand Vac are converted into blind hole or deep hole cleaning system by having the unit in vacuum mode. Then drilling a hole in the blow off end, and running a small tube to an attachment put over the vacuum end. This attachment is put flush over the deep or blind hole, and the tube blows into the hole, taking out the dirt and debris which is where the vacuum portion is supposed to take out. However, the problem with such units is that the blown air from the small tube works “against” the vacuum or suction effect of the main unit. While they work to some extent, it does not always clean effectively, especially if sticky or heavy material and debris is stuck in the hole.  

The Nex Flow Blind Hole Cleaning System does not use the above method, so as a result it provides a much more reliable result. In fact, it does not use vacuum at all. It works by blowing strong, high pressure air through various lengths of small tube (depending on the depth of the hole up to a depth of 52.5 cm or 20 inches). The hole is completely covered by a larger rubberized adaptor to prevent debris from flying out. There are three different adaptor sizes depending on the diameter of the hole (16 mm, 20 mm and 25 mm diameters). Attached to the adaptor on the air gun which is part of the system, is a removable collection bag that collects the dirt and debris that is blown out. Simple but very safe and effective in that all the debris is contained by the adaptor which is flush with the hole.

You cannot use just a safety gun for this application because the material removed will scatter making a mess and can also be dangerous. Likewise – it is fairly impossible to vacuum out deep hole because the vacuum force is typically not strong enough. A combination of blowing and vacuuming also does not work because the effects counteract each other (it’s like pushing and pulling at the same time). Therefore many chooses our Blind Hole Cleaning System for its safety and effectiveness.

In Summary

The next time you consider using compressed air for industrial cleaning, don’t forget to think of your application. Whether you choose Nex Flow’s Safety Air Gun, X-stream Hand Vac or our Blind Hole Cleaning System depends on what you are cleaning. A smaller safety gun may be sufficient to clean a small area. For larger area, perhaps a Hand Vac will do. For Heavy duty cleaning – you may want to consider the Heavy Duty Safety Air Gun and for deep or blind hole you would want to choose a special system like the Blind Hole Cleaning System.

Plan With Nex Flow CAD Models Today!

Some product manufacturers require you to register your personal data to obtain drawings and technical data. Nex Flow does not – as we believe “information that will help you in choosing your product should be free and accessible”. Nex Flow has faith in its products, quality and performance and strive to be there for you when needed. Hence, we do not interfere with the privacy of our product users just because a drawing is needed. We truly believe that our transparency, service, openness and good value can help to optimize any plant in terms of efficiency, energy use, sound levels and much more.

If you would like to receive a monthly update from us – you can opt in to our mailing list in which you can cancel at any time. We consider all customers to be partners treated with respect and that – means reasonable access to information that is required for you to work easily and privately.

One of the most useful information required by anyone utilizing Nex Flow products is the products’ performance but they also need to know if the products will “fit” into an application location. Machine builders and designers require drawings of product to be able to easily incorporate them into their designs. This is the very reason why we openly provide our drawings and dimensions to designers and users so you can best choose the product that “fits” your application.

Four drawing formats provided are:

The most common products where these drawings are utilized are:

The reason being that these products are typically part of a production line that have to be placed and oriented a certain way to work properly and to be assured that they fit for the application.

Other Nex Flow products also have these drawings available even if they are not necessarily incorporated into an initial product design. For example, Tool Coolers, Adjustable Spot Coolers and Mini Coolers come with magnet attachment so they can be mounted easily onto a machine. Sometimes these products are used intermittently because they are not always needed for a particular application or they are moved around and shared between several machines but the information is still necessary to visualize how they can be mounted.

All Nex Flow products need to be connected to a compressed air supply lines, filters, regulators and other types of in line equipment, most often supplied separately by others (although also available by Nex Flow). Machine builders and designers typically go direct to manufacturers of individual products because that is the way to get the best price as well as the technical data and drawings needed. End users usually have standard or existing suppliers for many of the accessories as well.

Air gun drawings are useful to give an idea of how the guns can fit into a person’s hand. There are many low cost – frankly cheap – air guns on the market but many times they are not very well designed for comfort. If the air guns are used extensively, a drawing will help visualize its use in your operation. Of special importance would be heavy duty air guns used for difficult air blow off applications. They need to be especially ergonometric to maximize comfort for the user.

The dimensions of items used in places where space can be a premium is also especially useful – such as vortex tube operated Panel Coolers which are mounted onto control panels but also used for cooling items such as cameras, and vortex tubes themselves. Panel Coolers are normally mounted on the top of control panels and there has to be enough space on the top of the panel, otherwise a side-mount should be used.

Static control technology is another item where drawings are useful in placement of product.  Static eliminators and their distance to the product is critical for their effectiveness and they also require a power supply near proximity to the static bar.

Having easy and anonymous access to these drawings makes the job of designing and choosing a product easier, more efficient and also helps to protect the work of the people using the information freely offered by Nex Flow.

The Coandă effect is the tendency of a stream of fluid (air or liquid) coming from an opening to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops. It can also be described as the tendency of a fluid to adhere to the walls of a convex surface.

Commonly a free jet of fluid entrains and mixes with its surroundings as it flows away from a nozzle. The key to the Coandă effect is that when the jet of air comes close to a curved surface, it remains close to the curvature even if the surface is curved away from the initial direction of the jet of fluid. This effect can be used to change a stream’s direction. In doing so, the rate at which the jet mixes are often significantly increased compared with that of an equivalent free jet.

When the fluid increases in speed, the pressure decreases, and this pressure imbalance results in the flow being pushed against the surface by the atmosphere. This means that even if the surface curves away from the direction of flow, the flow keeps sticking to it because the atmosphere is “applying” pressure so the liquid sticks to the surface. This continues until the flow slows down and mixes with ambient air taking away the pressure difference.

This effect is quite widespread in its applications – from airplanes to windshield washers in automobiles and even in air conditioning unit designs and their placement.

Bernoulli Principle and Coandă effect: Their Contributions to Flight

Daniel Bernoulli (1700-1782) discovered an effect named after himself over 300 years ago called the Bernoulli’s Principle. Air behaves like a liquid and when air moves, the pressure around the air parcel decreases. He discovered that if you can move air along a surface, the pressure on that side of the surface will be less than the pressure on its other side. This principal is used to lift airplane wings on aircraft.

The Bernoulli principle describes how planes fly. Aircraft wings have curved top sides and the bottoms are relatively flat. When moving, air hits the front edge of the wing causing some of the air to move up over the wings and the rest to move below the wing. As the upward moving air must follow the curvature of the wing and travels further than the air moving under the wing to reach the back edge at the same time, the air pressure on the top of the wing is reduced according to Bernoulli’s principle. The resulting higher pressure under the wing, lifts the aircraft. This lifting effect pushes the wing upwards and keeps the aircraft in flight.

Daniel Bernoulli : https://en.wikipedia.org/wiki/Daniel_Bernoulli

Though Bernoulli’s principle is a major source of lift in an aircraft wing, a Romanian aerodynamics pioneer engineer, Henri Coandă (1885-1972), discovered another effect that also helps produce lift. Henri Coandă, built the first jet aircraft in December 16, 1910 with his partner Gianni Caponi (another aviator). The plane, called the Coandă-1910, was a 4-cylinder piston engine used to power a rotary compressor. It was displayed in Paris at the Second International Aeronautical Exhibition and, unlike all other planes at the time, the Coandă-1910 did not have a propeller. The motor-driven turbine of his specially designed aircraft sucked the air through the turbine, while the exhaust exited from the rear. This design drove the plane forward by propulsion. Coandă noticed that the airflow was attracted to nearby surfaces. In 1934, Coandă obtained a patent in France for a “method and apparatus for deviation of a fluid into another fluid.” The effect was described as the “deviation of a plain jet of a fluid that penetrates another fluid in the vicinity of a convex wall.” The first official documents that explicitly mention the Coandă effect were two 1936 patents by Henri Coandă. (Coandă effect, Retrieved from Wikipedia on Dec 12, 2018). Unfortunately, the first flight ended in an accident and he could not raise enough money to continue his research.

“A moving stream of fluid, when in contact with a curved surface, will tend to follow the curvature instead of continuing to move in a straight line.”

Like the Bernoulli effect, the Coandă effect also describes how an airplane’s wing lifts. The difference is the Coandă effect describes the angle of attack, which is the angle between the wing and the direction of the air flow, as shown in the following diagram:

The angle of attack indicates the wing’s tilt with respect to the oncoming air. To lift the wing, Newton’s third law says that there must be an equal force acting in the opposite direction. If we can exert a force on the air so that it is directed down, the air will exert an upward force back on the wing. As the angle of attack increases, so does the lift. If the angle of attack is too great, the air flow will stop following the curve of the wing and a small vacuum is created behind the wing causing vibration and decreases the wing’s efficiency.  The wing’s efficiency is important because it directs the airflow downward and pushes up on the wing to produce lift. If the surface is not too sharply curved, the jet of air can follow the surface. The forces that cause these changes in the direction of flow causes an equal and opposite force on the surface along which the jet/stream flows. These Coandă effect/forces causes lift depending on the orientation of the jet and the surface to which the jet/stream adheres. This effect can be induced in any fluids including water.

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Applications of Coandă effect in Compressed Air Industries

Henri Coandă was the first person to recognize the practical application of the phenomenon in aircraft development. The effect is used to power pneumatic production equipment, air operated lathe chucks, pressure clean parts, and to convey or cool components during production for the following industries:

• Chemicals
• Pharmaceuticals (i.e. ventilators)
• Food & Beverage
• Aeration and Agitation
• Semiconductor & Electronics
• Medical Breathing Air
• Automotive for tires and breaks
• Manufacturing

Compressed air is also used for maintenance, power washers, and other cleaning tools.

In air conditioning, the Coandă effect is exploited to increase the throw of a ceiling mounted diffuser. It cools without the use of chemicals. Because the effect causes air discharged from the diffuser to “stick” to the ceiling, it travels farther before dropping for the same discharge velocity than it would if the diffuser was mounted in free air, without the neighboring ceiling. Lower discharge velocity means lower noise levels and in the case of Variable Air Volume (VAV) air conditioning systems, permits greater turndown ratios. Linear diffusers and slot diffusers that present a greater length of contact with the ceiling exhibit a greater Coandă effect.

Henri Coandă : https://en.wikipedia.org/wiki/Henri_Coand%C4%83

The Coandă effect is used in compressed air flow amplification technology to create energy efficient and noise reducing air amplifiers or movers, jets, and knives used in blow off applications. This effect helps to save energy and meet  Occupational Safety and Health Administration (OSHA) standards in compressed industries.

Air Amplifiers or “Movers”

A compressed air flow amplifier works by entraining air along with compressed air. The amplified air utilizes the Coandă effect to draw in surrounding atmospheric air while consuming only a minimal amount of compressed air. These products can amplify airflow up to 17 times with reduced noise levels. The air follows the profile of a pipe outward to cool or dry a surface. Compressed air mixes with ambient air drawn into the device causing the resulting mixed air to have a higher flow and force than the starting ambient air. Air movers are more effective for cooling because of the high velocity outlet flow when compared to flat nozzles. The force produced for blow off decreases as the amplifier outlet diameter increases.

The increased flow reduces the amount of compressed air required. Allowing the Air Amplifier to be used in applications like venting fumes and smoke, conveying low weight materials, and entraining a high volume of air to cool, blow off, or dry.

Air Jets

Compressed air jets generate a high-volume air flow while minimizing compressed air consumption. The compressed air is distributed through an annular ring and is directed towards the outlet using the Coandă effect. This results in the entrainment of surrounding air and results in a great force and velocity compared to the minimized volume of compressed air needed.

Air Knife

Air knives use the Coandă effect for product cooking, drying, and cleaning. An air knife system can be found in most manufacturing and packaging plants such as:

• Food packaging for drying; cooling; removing spills from packaging materials
• Bottle plants for drying cans and bottles
• Metal forming for cleaning; cooling; galvanizing; roll forming
• Foundries and casting plants for cleaning and cooling

For example:

The coating thickness in hot-dip zinc galvanizing process is often done using the gas wiping through an air knife system that uses the Coandă effect. The thickness of the galvanized zinc is of practical importance in determining the quality of product. Such a gas wiping method causes a technical problem of splashing from the strip edge to have a harmful effect on the performance of the galvanizing process and the product quality. The results obtained from “a study on the air knife flow with Coandă effect” Journal of Mechanical Science and Technology 21(12):2214-2220, December 2007, show that Coandă air knife system (nozzle) effectively reduces the splashing problem, leading to improvement of the whole galvanizing process.

Nex Flow Air Products Corp. specializes in the manufacturing of compressed air products for blow off, cooling and moving to optimize energy use and safety.

Air knives can be compressed air operated or blower operated and different factors determine which is optimal to use. This article will be focused on the different ways you can set up a compressed air operated air knife. Compressed air operated air knives are used primarily for drying, cleaning, and cooling and also for coating control and drying. There are multiple ways to set-up an air knife system depending on the application.

Below is a list of five common application and the basic suitable set-up

1. Drying or removing liquids from the surface of parts
2. Debris blow off from parts with special focus on how to remove static electricity from plastic parts that need to be cleaned
3. Coating control on parts when a coating is applied and needs to be spread evenly over the part
4. Drying or setting of a coating once applied to the part
5. Cooling of materials

Drying or Removing Liquids

Compressed air operated air knives are excellent for drying applications especially when drying relatively smooth and flat surfaces because of the high shear force. Blower operated systems often rely on heat as well as large blower mass flow to remove liquid but this can often leave stains on the surfaces left over from chemical residue. Compressed air operated units will have the added energy to remove all the liquid minimizing any possibility of stains. In addition, you need much less of a footprint to dry in any conveyed system as any liquid droplets left after drying are so small they evaporate very quickly. In these applications the air knife flow is directed against the direction of the moving product about 3 degrees in slow moving situations and incrementally increased to as much as 30 degrees for fast moving applications. The actual pressure used depends on speed and viscosity of the fluid removed and the roughness of the surface where the liquid is deposited. The greater the speed, viscosity and roughness, the more pressure is needed. Input air pressure can range anywhere from 60 to 80 PSIG.

Debris Blow Off

Compressed air operated air knives are also ideal in blowing off relatively light debris as compared to blower systems for the same reason as when dying, ie: light scrap off conveyors, dust and debris. The same rules apply regarding the angle of the air knife as with drying and is again directed against the direction of the moving target.  It can be 3 to 30 degrees depending on speed but also depending on the nature of the material being blown off. For dust blow-off – it can be treated like liquid. For larger material or clumps of product, the angle can vary widely and needs to be tested for best effect in cleaning. Pressure however can often be very low (as low as 30 PSIG for light dust and debris) but of course can ramp up to 80 PSIG for heavier material. For very heavy material, the air gap of the air knife can be opened up for more force and power but that will also increase the amount of compressed air needed. For particulate or objects that need to be removed but only show up intermittently, a sensor system can be set up to detect the material and turn on the air supply only when needed to conserve energy as compressed air operated air knives can be instant on and off in operation. When having to clean particulate for statically charged surfaces such as plastics or film, an ionizing bar (static eliminator) can be attached to the air knife. When used in conjunction – unless the particulate is also very sticky – pressure as low as 30 PSIG and even less is capable of de-dusting a statically charged surface. Learn more about how a static eliminator works.

An example of such an air knife with a static bar is the Air Blade Ionizer. If noise is a concern a Silent X-stream® model is also available. For very high charges or fast moving target, a stronger static bar may be used as with the our Triple X Air Blade Ionizer.

Coating Control

A compressed air knife with a very sharp edge air flow such as the X-Stream Air Blade® are ideal for use in controlling the level of coating applied to a product. The sharp, even and targeted flow from this unit can control the amount of coating on a product as the coating is first applied, then spread with the help of the air knife. The required pressure depends on speed and the depth required for the coating but easily controlled with a regulator and can vary widely depending on the viscosity of the costing as well. In coating control the laminar flow produced is important and gives much better control than the more turbulent flows produced by blower operated systems. In coating control the angle of the air knife is usually around 3 to 5 degrees due to the slower speeds involved.

Drying or setting of a Coating

Ever wonder why compressed air gets cold? There is a slight cooling effect when air leaves a compressed air operated air knife as the air goes from high pressure to low pressure. Air flow is amplified as atmospheric air is entrained along with the compressed air but there is still a slight cooling effect. This cooling effect assist in helping to dry or set a coating once applied to the product to ensure an even finish. Pressure used is typically quite low at 20 to 30 PSIG and angle around 3 degrees against the flow of material.  

Cooling of Material

As mentioned above, there is a slight cooling effect which helps when used to cool materials. But in addition to the cooling effect, the laminar flow and high velocity of the air produced by a compressed air operated air knife can “cut” through the boundary layer produced by heat generated in a hot target and help cool the material. The cooling occurs due to the wind chill effect. How fast the material can be cooled depends on several factors. The higher the initial temperature, the faster it will cool, and the rate of cooling will slow logarithmically as the material gets cooler. Dwell time is also important. It is no question that you need time to cool an object. So when cooling with an air knife the product should travel slowly. Alternatively you can use several air knives, one after the other, to have enough exposure or dwell time to blow on the product and cool.  The angle of the set-up should again be about 3 degrees with pressure typically at 80 PSIG to get the optimum mass flow and velocity for cooling.

So whether drying, cleaning, controlling coating, setting a coating or cooling, compressed air operated air knives offer an economical and viable solution. To further reduce your compressed air energy consumption – don’t forget to check out this article!

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Compressed Air Uses in the Automotive Manufacturing Industry

Advanced computer technologies, automated assembly systems, and high-quality compressed air systems have changed the automotive manufacturing industry. Consumers can purchase safer, more fuel-efficient and reliable vehicles today than ever before. Using compressed air during manufacturing can also save energy and money during assembly.

Uses of Compressed Air in Automotive Manufacturing

Over the last 100 years, automotive manufacturing has been enhanced by the introduction of compressed air in the assembly line to increase worker’s safety and the overall efficiency of the manufacturing plant. It is used as a tool in almost every step in the process of car manufacturing from painting, cleaning, engine and vehicle assembly. It is also used in car tires and in garages/body shops.  The typical uses of compressed air in automotive manufacturing include:

• Air operated robots
• Plasma cutting and welding to help speed and reliability
• Air tools are preferred to electronic tools because they are light and easy to use
• Breathing Air filters to increase air quality
• Tire inflation
• Automobile finishing

Cars are now made of more durable and light-weight composite materials including plastics. During assembly, compressed air tools create the auto parts and power the lifting, positioning, and moving, fastening machines. It is used to form critical vehicle components such as stamping door panels and trunks.

Both cleaning and painting processes utilizes compressed air. The bare vehicle is inspected for defects and cleaned before painting.  Any contaminants in the air supply will cause expensive re-work, spoilage, and production loss. Clean, dry, oil and contaminant-free compressed air is used to achieve a perfect mirror finish during painting. The compressed air used must have no water or contaminants while painting the car to ensure an even finish. Garages and body shops also use low pressure oil-free compressed air to operate their spray guns. Compressed air is used to agitate the paint in a bath to prevent clumping and mix the color for consistency. Paint is propelled through guns or robots onto a clean metal car body surface using compressed air. To have a consistent reliable paint spray it is critical to choose the right size and type of compressor. Use a compressed air dryer and coalescing filters to remove any naturally occurring moisture to achieve a high-quality paint finish.  

Compressed air conveying system has eased heaving lifting on the assembly line that used to be done by humans. The compressed air conveyor systems use clean dry air to create a thin film of air between the work table and the floor. Using a conveying system, parts are sent through the production line. The major components, including gas tank, suspension, axles, breaks, and steering systems, are installed in the car. Tools such as air-powered wrenches fasten and screw components in place. These tools also remove nuts and bolts with an air ratchet. Grinding and cutting metal is done using a small air powered saw. Robotic machinery now uses compressed air to lift, transport, and position heavy components that were once placed by hand. Compressed air is used to install quarter panels, side panels, and roofs in place. Now that the heaving lifting is done by these air operated machines, the assembly line is much more efficient and safer for workers.

The consistency and reliability of a compressed air tools is the reason for their use in body shops.  Often air sanders are used to smooth out rough metal pieces. It is recommended to use a pneumatic sander since it weighs less than their electric version and are much more reliable in dusty environments.

Results of Contaminants in Compressed Air During Manufacturing

According to the Compressed Air and Gas Institute (CAGI) and the International Organization for Standardization (ISO), the major contaminants in compressed air are oil, water, microorganisms, and solid particles.  Microorganisms are beyond the scope of this article.

ISO 8573 has nine sections that describes compressed air. Section 1 provides a list of contaminants and purity classes. The other sections address sampling techniques and analytical methods for various contaminants.

The following is a list of negative results when compressed air is not clean during automotive manufacturing various types of contaminants.

Oil can:

• Damage equipment
• Cause costly equipment replacement
• Expensive downtime during manufacturing
• Prevent paint adhesion to surfaces
• Paint to crack, flake, or bead
• Create future corrosion or the final finish on a car

When compressed air draws in atmospheric air, it is compressed about a dozen times the normal atmospheric pressure. Atmospheric air naturally contains moisture. The amount of moisture depends on the location (altitude) and season.  In these conditions, the water/moisture will begin to condense since compressed air cannot hold the same amount as normal air. This condensation increases as the compressed air moves through the system/gun and cools. These effects are more evident during the summer with higher humidity. Water can:

• Cause moisture to get pulled back into the compressed air system
• Cause negative visual and textural effects on the finish: spotting or “fish-eyes”
• Stick to pipe walls
• Collect in receiver when the air velocity reduces
• Squirt out of the nozzle with the compressed air
• Collect in the low point of the pipe – then is released at once
• Block the path of the compressed air

NOTE: the condensed water would also have other contaminants collecting in the low point of pipes resulting in a nasty mixture of oil and moisture.

Solid Particles, such as rust, dry particles, and aerosols, can:

• Clog nozzles
• Affect the surface of the finished product

Recommended Best Practices for using Compressed Air in Automotive Manufacturing

It is recommended to replace older units with oil-free centrifugal air compressors piped to heat off compression dryers. The energy savings may not be significant but the benefits of improved air quality and reduced maintenance and water cooling costs.

Reduce compressed air consumption by repairing purge controls on dryers and reducing overall demand. Repair compressed air leaks. Replace timer drains. Replace air operated diaphragm pumps with electric ones. This will modernize air compressors into oil free centrifugal technology able to use heat-of-compression dryers. This reduces maintenance and water-cooling costs with long-lasting and efficient air compressors.

The following simple things can be done to remove oil from your compressed air system:

• Multi-staged filtration between the compressor and the tool
• Pneumatic systems can be filtered at the compressor or point of use

The following simple things can be done to remove water from your compressed air system:

• Check your compressor daily
• Fit a water trap or spinner just before your downstream equipment
• Use desiccant air dryers range form -40 degrees to -100 degrees of dew point – which is helpful in painting, printing, and instrument applications.
• Use deliquescent air dryer, which removes the least amount of water vapor and is not usually found in critical applications where air needs to be very dry. It uses salt-like tablets to absorb water vapor from compressed air.
• Manually drain receiver tanks to rid the system of moisture in the air compressor system or use a timer-based drains and pneumatic auto drains. Remember it is illegal to pour untreated condensate down the drain. It is recommended to treat the water before disposing of it.
• Use a pneumatic water separator can remove up to 99.99% of water and oil from the air supply.
• Use a refrigerated air dryer.  Chilling air lowers the water between 34 and 40-degree dew-point, which is enough for most applications.

Solid particles can be removed by:

• Dry particulate filtration through direct, inertial, or diffusion movement
• Vapor and aerosol filtration through coalescing or adsorption.

Evaluating the Energy Consumption of Compressed Air

Determining the demand on a compressed air system is important. To calculate the load profile, do the following:

• Interview the plant personnel
• Review historical flow records
• Observe loads on the modicum (little) system
• Count the number of machines requiring compressed air in the plant
• Are there plans for new machines? What are the requirements?

From the above observations determine the current maximum possible peak, current peak, average production flow, and low production flow in cfm.

To determine where your current compressed air system can be enhanced to save money, consider the following:

• Ensure that the current compressors are well maintained, installed, and power efficient units.
• Determine the age of the unit
• Determine their maintenance schedule. Does the equipment need lubrication? Does older equipment need to be replaced?

NOTE: Older units are more difficult and expensive to maintain since the parts are no longer available

Factors to Consider to Size and Install an Air Compressor:

This is a list of items to consider when determining the size of your compressor:

• Air pressure requirements based on manufacturer recommended guidelines. The incorrect pressure results in poor tool and machine performance.
• Air demand (psi and CFM)
• Compressed air storage. A simple guideline is 4 to 5 gallons of air storage per CFM.

Also consider the location of the air compressing equipment. The compressor should be installed on a level surface. Follow the recommended guidelines for spacing:

1. Serviceability and access
2. Air circulation and ambient room temperature
3. Location of Power distribution center
4. Ambient air cleanliness
5. Keeping the area around the air compressor clean
6. Employee health and safety – noise and vibration levels.

Nex Flow recommends several products that can help improve the operations of everything from small body shop projects to the more demanding tasks in the automotive manufacturing site. Here is a look at some of their top-performing products applicable to the automotive manufacturing

• Air amplifiers – compact, low cost air flow movers that are maintenance free. The unit uses the Coandă effect to drain in and amplify air flow up to 17 times results in dramatically reduced noise levels. These devices are used for cooling and venting.
• Air nozzles convert pressure to flow efficiently. All Nex Flow Air Nozzles meet OSHA standard CFR 1910.242(b) for dead end pressure and noise levels are dramatically lower in addition to having lower energy use.
• Ring Vac® air operated conveyors are simple, low cost solution compared to other pneumatic conveying systems. Simply clamp a standard hose size to each end of the Ring-Vac® to create this high energy conveying system. There are no moving parts which lend to maintenance free operation while capacity and flow are controlled with a pressure regulator.

What is Industrial Ventilation?

Industrial ventilation is a mechanical system that brings in fresh outdoor air into the workplace (factory or manufacturing plant) and removes contaminated indoor air.  Ventilation is used in a factory to provide a healthy and safe working environment for employees and to remove or have control over contaminants released in an indoor work environment.  The ventilation could be achieved by opening a window (natural) or using fans/blowers (mechanical means). Common pollutants that are removed using an industrial ventilation system include: flammable vapors, welding fumes, dust, mold, asbestos fibers, oil mists, toxic chemicals, moisture and more.

Installing proper industrial ventilation is crucial for providing a safe and healthy environment for workers. They are critical to monitoring indoor air quality. A well-designed ventilation system will bring the air into the workspace at a specific speed creating the required air pressure to ensure cost savings for heating and cooling.

The purposes of a well designed industrial ventilation system are:

• Provide a continuous supply of fresh outside air
• Maintain temperature and humidity
• Reduce hazards for fire and explosion
• Remove or dilute contaminants in the air

An industrial ventilation system consists of two subsystems: the fresh air supply and an exhaust system.

The fresh air supply system includes an air inlet, air filtering equipment, heating and/or cooling equipment, fans, ductwork and air distribution registers.

The exhaust system has an air intake area and ducts to remove contaminated air from one area to another area, an air cleaning device, discharge stacks and fans.

Limitations of Industrial Ventilation Systems

Some limitations of many if not all industrial ventilation systems:

• They require ongoing maintenance because of contaminant build-up within the system, especially filters.
• Regular and routine testing is needed to identify problems early and implement corrective measures.
• Only qualified persons should make modifications to a ventilation system to make sure the system continues to work effectively.
• Making unauthorized changes to the duct system will pull air into the system from the new location resulting in reduced air flow from other locations. The entire ventilation system airflow will be affected resulting in rapid plugging of the system preventing the system from adequately removing contaminants.

Types of Industrial Ventilation Systems

There are three types of industrial ventilation systems: Dilution, Local Exhaust, and Indoor air quality ventilation

Dilution System

A Dilution system reduces the number of contaminants in the air by mixing the contaminated air with clean, fresh air. To install a dilution system, large exhaust fans are installed in the walls or the roof of a factory. This type of industrial ventilation system is used when:

• Air pollution is low and toxicity level is low to moderate.
• Contaminants are vapours or gases
• Emissions are uniform and widely dispersed
• Recommended for moderate climatic environments
• Heat is removed by flushing to the outside
• Mobile contaminant sources are controlled

Advantages of Dilution:

• Needs less maintenance.
• Lower equipment and installation costs
• Recommended for small amounts of low toxic chemicals
• Effectively controls flammable or combustible gases or vapors
• Used for mobile or dispersed contaminant sources

Disadvantages of Dilution:

• Not recommended for highly toxic chemicals
• Does not completely remove contaminants so it is not recommended for high concentrations of dust, fumes, gases, or vapors
• Large quantities of heated or cooled makeup air is required.
• Not recommended for irregular emissions of contaminants.

What is Make up air?

Make up air is the air used to replace the air that was extracted from the workplace. If not replaced, the workplace could become “starved” of air and result in negative air pressure. The negative air pressure could increase resistance on the ventilation system resulting in less air being moved. To determine the pressure in a workplace:

1. Open a door 3 mm and hold a smoke tube in front of the opening. If the smoke is drawn into the room, the room has negative pressure.  If the smoke is pushed away from the room the room has positive pressure. If the smoke raises straight into the air, then the pressure in the room is the same as the outside pressure.
2. Check the resistance when pushing or pulling a door.
3. If the room has a negative pressure – an easy solution is to install a separate intake fan, located away from the exhaust fans to bring fresh uncontaminated air from the outside. Ideally, the air is clean and warmed in the winter or cooled in the summer; as needed. Check some common questions and optimal placement of intake fan here (What are the main features of dilution ventilation?).

Local Exhaust System

A Local Exhaust system captures contaminants at the source and ejects them outside.  It functions on a principal that air moves from high pressure areas to low pressure areas. This difference in pressure is created by a fan that draws air through the ventilation system.

This system is used in areas of high air contamination concentration where there is a greater risk to of exposure to employees. The ventilation system is used for isolated or contaminant sources. This system requires:

• A hood or other device to capture the air pollutants at the source.
• Ductwork as close to the source of contaminants as possible to move the contaminants away from the inside. The material must be compatible with the airstream
• A quality air filter system to clean the air as it moves.
• A fan that moves the air through the system and blows it outdoors
• A stack through which the contaminants are removed.
• The workers are considered in the design, installation, and maintenance of this system.

NOTE: The fan must be the proper type, wheel, arrangement, and size for the application. The fan may require spark resistant construction or other special options.

This system can handle removing many kinds of pollutants including metal fumes and dust. It uses less energy than dilution systems.  This type of industrial ventilation system is used when:

• Inconsistent emissions over time
• High concentration of hazardous materials
• Point sources of contaminants
• Workers are close to the source of contaminants
• Factory is in a severe climate location
• It is required not to turnover air in the factory

Advantages of a Local Exhaust Ventilation System:

• Requires less makeup air because less quantities of air are exhausted
• Reduced energy heating and cooling costs
• Captures the emission at the source and removes it
• The best type of ventilation for highly toxic airborne contaminants, fumes, gases, vapours, and dust.

Disadvantages of a Local Exhaust Ventilation System:

• High cost to design, install, and maintain
• Requires regular maintenance, inspection, and cleaning

Indoor Air Quality Ventilation

Indoor air quality ventilation, which provides fresh heated or cooled air to buildings as part of the heating, ventilating and air-conditioning system (HVAC). The parts of an HVAC system include:

• Air inlet
• Air filtering equipment
• Heating/cooling equipment
• Fan
• Ducts
• Air distribution registers
  

The exhaust system consists of:

• Air intake area
• Ducts to move air from one area to another
• Air cleaning device
• Fans to bring the outside air in the factory and to bring contaminated indoor air outside
• Stacks

Nex Flow® Venting Solution

1. Fume and Dust extractors
2. Ring Vac®
3. Air Volume amplifiers

Fume and Dust Extraction system is designed for portable use, especially for intermittent (on- off) applications. They are rugged and long lasting.  This option is beneficial because of its low cost with reduced noise. For soldering applications, spot welding operations, a small, portable less expensive unit using a small amount of compressed air is more cost efficient than a heavier electronically operated unit.

The system is Low cost and durable and consists of:

• An adjustable air amplifier
• 2” lock-line hose, which draws in a large volume
• Magnetic base – which secures to a metal working table
• A hose can be clamped onto the outlet of the amplifier to take the fumes and dust into a container or out to another area.

Ring Vac® may be added and used to convey collected material beyond 10 feet (3 meters). The Model 40002FMS Stream Vac® (link to product) is affordable compact air cleaning system to remove dust, fumes, and other air pollution from work places. When connected to 10 feet (3 meters) 2” hose compressed air line, the system will remove up to several hundred cubic feet of air with welding and soldering fumes, particulate from local grinding operations, smoke and particulate using very little compressed air.   

Air Amplifiers also called “Air Movers” – can be used for moving a large volume of air. Air Amplifiers uses a small parcel of compressed air to produce high velocity and volume, low pressure air flow as the output.  They are ideal blowing or cooling and for venting. Air amplifiers are used to convey powders and dust, exhaust tank fumes, and moves air 12 to 20-fold in duct appliances to 60 times in area with no ducts. The amplifiers use a small amount of compressed air to draw in a flow of up to 17 times the air consumed to remove fumes quickly and efficiently for venting applications. The fumes can be ducted away, up to 50 feet (15.24 m), and the amount of suction and flow is easily controlled.  

If a large amount of air borne dust or fumes need to be collected and moved a long distance, the air amplifier enhances the air conveyor ability to convey these materials over long distances. The reason is that air conveyors produces high vacuum but move less volume as compared to air amplifiers that move high volume but creates less vacuum. Nex Flow air conveyor systems are manufactured in anodized aluminum for most applications and in 304 Stainless Steel for high temperature and corrosive environments. 316L Stainless Steel air operated conveyors are available for food and pharmaceutical applications. An XSPC range conveyor is also available for moving materials that could clog. Air Amplifiers are lightweight, compact and portable so any application where that can be an advantage is ideal for their use, especially if the use is intermittent minimizing the real energy cost of compressed air.

The following accessories are available with Nex Flow air amplifiers:

• Hose or pipe to collect or transfer materials, fumes, and dust
• Filters
• Mounting systems including brackets
• Regulators
• PLCFC
• Stainless steel shims for maximum product lifespan
• Pneumatic water separator
• Manual valves
• Replacement parts
• Flanges

NOTE: Pipes reduce the air amplification by 10:1 due to back pressure but still provides more efficient air amplification because venture systems move air or vent gas.

Nex Flow air amplifiers are compressed air operated devices that are often used for local ventilation due to their portability.  They are not electrically run so there is no explosion risk. Compact and rugged, they are built to last. If existing systems are not sufficiently strong enough to move the contaminated air, then Air Amplifiers can boost these systems and overcome the losses. This deficiency may be caused by a pressure drop at ventilation entrances.

Filtration is important for maintaining the effective and optimum operation of all Nex Flow air operated products. All Next Flow products used for conveying. such as air amplifiers, air operated conveyors, etc. require clean compressed air. It is essential to use filters to remove water and oil from the compressed air lines. These filters are installed upstream from the air amplifier or air mover in the industrial ventilation system. Air filters should be sized to handle the maximum air flow expected for conveying the contaminated or clean air they are moving. Nex Flow water and oil removal filters are 5 microns and 0.3 microns respectively.

Best Practices for After Installation

It is important to follow through with your employees and train them on the industrial ventilation system. They should be aware of the following:

• How the exhaust system is designed and the intended use.
• The use of the flow restrictors, diverters, and baffles that can alter air movement.

• Keep all hoods, slots, and duct work openings clear of debris, obstructions and buildup which reduces the amount of air entering the ventilation system
• The ideal location to position the employee and the equipment to maximize the amount of air movement into the exhaust hood.
• Employees should continuously observe the ventilation system for damage and flow restrictions. They should be aware of who to report damages to.  A manometer, used to monitor pressure, is a good method of judging if the system require maintenance.
• An employee should perform regular system maintenance, such as changing filters. This will reduce the amount of resistance in the system and improves the systems efficiency.

What does all this mean?

It is important to properly design your industrial ventilation system to achieve the following:

• Provide continual fresh air supply
• Protect workers from heat stroke or cold temperatures
• Reduce fire or explosion risks
• Reduce exposure to airborne contaminants

Although all ventilation systems consist of the same basic principals, each system is designed specifically to meet the requirements of the work environment including the type of work and the rate of contamination release in the factory.  Some important standards and items to consider when designing an industrial ventilation system are:

• OSHA and EPA regulations
• Proper duct design
• Air sampling
• Types of materials used in the construction of the system
• Hazard reduction
• Administrative controls
• Efficient hood design
• Proper fan selection
• Fire and explosion hazards
• Pollution control equipment selection

Our experts at Nex Flow® can help you choose the industrial ventilation system best suited for your manufacturing site or factory. Please don’t hesitate to contact us for more information about our ventilation solutions from a simple Air Amplifier to our Ring Vac® and Fume and Dust Extractor.

Recommended compressed air standards and related terms

There are several major standards to consider with the use of compressed air – two with regard to air quality, one for compressed air safety and any local standards related to noise.

Since compressed air is used in so many areas where it can come in contact with food or medicines, air quality standard is probably the most important standard related to compressed air use.  ISO 8573, established in 1991 is a multi-part standard for compressed air quality to facilitate compressed air system component selection, design and measurement. Part 1 classifies contaminant type and assigning air quality levels, and Parts 2 through 9, define testing methods to accurately measure a full range of contaminants within the end user’s facility.   The ISO 8573 Air Quality standard does not however address how manufacturers are to test and rate the filters. The ISO 12500 filter standard was developed to address this issue and establishes how manufacturers test and rate compressed air filters by defining critical performance parameters (namely, inlet oil challenge, inlet compressed air temperature and pressure measurement techniques) that will deliver certifiable filter performance information suitable for comparative purposes.

ISO 12500 is a multi-part standard, with ISO 12500-1 encompassing the testing of coalescing filters for oil aerosol removal performance, ISO 12500-2 quantifies vapor removal capacity of adsorption filters, and; ISO 12500-3 outlines requirements to test particulate filters for solid contaminant removal.

Occupational Safety and Health Administration (OSHA) standard 1910.242(b) requires that compressed air used for cleaning purposes must be reduced to less than 30 psig (pounds per square inch gauge, 204 kPa). Compressed air used for cleaning must only be permitted with effective chip guarding and personal protective equipment to protect the operator and other employees from the hazards of the release of compressed air and flying debris. Standard 1917.154, which addresses similar hazards in the maritime industry, explicitly prohibits the use of compressed air for personnel cleaning. While this particular requirement is not specifically applicable in the general industry setting, it is recognized as good practice for all industries.  Standard CFR 1910.242(b) is a major guideline for Nex FlowTM  in the design of their air saving nozzles, to keep dead end pressure under 30 psig.

Noise standards vary around the world. Compressed air, when exhausted from cylinders, air nozzles especially, produce noise – both impact noise and exhaust noise.  Please refer to our article on noise levels for more detail.

Terminology used in compressed air systems can be confusing, so we have defined some for you along with common units and conversions below (the terms do not include terms related specifically to the compressors themselves – just terms downstream).

Absolute Pressure – The measure of pressure compared to the absolute zero pressure of an empty space—e.g., a vacuum.  Expressed in pounds per square inch (PSI) or bar (BAR) or kilopascals (KPa). 1 bar equals 14.7 PSI equals 100 KPa

Actual Capacity – Also known as Free Air Delivered (FAD), this is the amount of gas actually compressed and delivered (at rated speeds and conditions) to a discharge system.  Expressed as cubic feet per minute (CFM) or liters (LPM) per minute where 1 CFM = 28.32 LPM.

Air Consumption – The compressed air consumed from the compressed air system by any machine, air tool or blow off device to operate expressed at a particular input pressure to the device and usually in SCFM or SLPM as defined further below.

Amplification Ratio – A term typically used with blow off devices such as engineered air nozzles, jets, air amplifiers, air knives to express the amount of increase in air flow compared to the compressed air used.  Should be expressed at a particular distance from the blow off device. It is usually and average over various inlet pressures.  

Atmospheric Pressure – The measured surrounding pressure of a particular location and its altitude.  Measured in PSI or BAR or KPa as explained above

Blow Off Force – The force produced by a blow off nozzle, jet, air knife or amplifier on pounds force or grams as a particular pressure at the device inlet, expressed at a particular distance from the device.

Free Air CFM or LPM– Air’s flow rate at a specified point and condition, which is then converted to surrounding conditions.

Actual CFM or LPM – Air’s flow rate at a specified point and condition.

Inlet CFM or LPM – Air that is flowing through the inlet filter or valve of a compressor (under rated conditions).

Standard CFM or LPM – The flow rate of free air that is measured and then converted to a uniform set of reference conditions.  Normally expressed as SCFM or SLPM.

Dew Point – The temperature point at which moisture starts to condense in the air, if the air continues to be cooled at a single pressure.

Filters – Devices to remove particles, moisture, and lubricants from surrounding air.

Gauge Pressure – Normally expressed in pounds per square inch (PSIG), this is the pressure most instruments are used to determine.

Intercooling – Process in which heat is removed from gas or air between the stages of compression.

Leak – An unintentional loss of compressed air to surrounding conditions of a compressor.

Pressure – The measure of force per unit area, conveyed in pounds per square inch (PSI) or bar or KPa as compared previously.

Pressure Dew Point – The temperature that water starts to condense out of air for a given system pressure.

Pressure Drop – A pressure loss in compressed air systems caused by restriction or friction. Expressed as PSI, BAR or KPa.

Rated Capacity – At a specified point, this is the volume rate of flow at rated pressures.

Rated Pressure – The measure of the operating pressure of air compressors.

Standard Air – Used in ISO standards, this refers to air at 14.7 pounds per square inch absolute (PSIA), 68°F (20°C), and dry (0% relative humidity).

FEATURED PRODUCTS

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Compressed air is a very important tool for food processing and packaging. Food production includes processes like canning, freezing, and dehydration. In this industry – compressed air is used for blow-off applications, cleaning, sorting, cutting, shaping, and conveying food products. It is also used to help form, fill, and seal cartons. The food production industry has approximately 1,300 facilities and employs 112,000 people for processing fruits and vegetables in the United States. The air must be free of contaminants before contact or non-contact with food products.  It is the manufacturer’s responsibility to know the composition of the air used to avoid product contamination. The air quality is the measure of these contaminants in the pressurized air.  If a component of the air has a harmful effect or makes the condition of the product worse – it is considered a compressed air contaminant.  The sources of contaminants in compressed air food processing environments could be physical, chemical, or biological hazards. They include: particles, microorganisms, water, and oil.

Each food processing plant has unique requirements. The goals are to guarantee compliance with standards, levels of food safety, and quality set forth by the FDA and other regulatory entities.  This is critical since food products are ingested by humans and animals.


To apply the appropriate regulatory process to for compressed air and food management systems, recognize the following regulatory organizations:

Sources of Contaminants

The possible sources of contaminants in food processing using compressed air are:

• Ambient air can contain anywhere between 5-25 grams of water, 1-5 micrograms of oil, and 10-100 bacterial parts per cubic meter
• Pipes may contain rust, shed metal, or plastic pipes may shed polymer particles
• Charcoal filters and canisters shed particles
• Sealing tape
• Rubber gasket pieces
• Condensed water, liquid, and oil already present in the system form vapor or aerosol.
• Airborne microbes
• Relative Humidity is a source of moisture in the air

NOTE: ISO 8573.1:2010, British Retail Consortium (BRC)  and British Compressed Air Society (BCAS) are specifications that identify potential hazards in the food processing industry.

Impacts of Contaminants

One cubic meter of untreated compressed air contains almost 200 million dirt particles and a lot of water, oil, lead, cadmium and mercury. (Validation of System for Air Quality, https://rastgar-co.com/air-quality/, retrieved November 2, 2018) The impacts of contaminants in a food processing plant are:

• Microbial and bacterial growth on products and equipment
• Corrosive particles landing on sterilized food
• Hazardous consequences to consumer health including the ingestion of hydrocarbons
• Contaminates could accumulate on food products.
• Corrode pipes causing blockages and reduces the life of filters, drains, and machinery in plants.
• Increased energy and money waste.

Understanding Air Quality Factors?

The factors that need to be understood in a food processing environment to improve air quality are:

• Assess the activities and operations that could harm the food product. This is a multistep process:

1. 1. Identify potential hazards
   2. Assess the risk of harm
   3. Assess the controls measures in place for appropriateness
   4. Prioritize controls and hazards for management
   5. Assess the need for extra controls by taking preventative steps to remove or reduce the chance of product harm or harm to the customer
   6. Schedule regular reviews to assess the adequacy of the controls in place

• Determine the extent that the food product is harmed by a potential contaminant
• Determine the likelihood of contamination.
• Understand the impact of air quality on the work zone, workers, and the product or service manufactured.
• Review Direct Product Contact, Indirect Product Contact, USP, and ISO 8573 air standards.
• Understand your requirements for safe food production.
• Engage the production engineers who are most familiar with air quality requirements. They are the resource to determine what needs to be removed from the air and which filter to use for the correct solution. The production engineer would also know the dampness of the air required: moist or dry.

• Determine the amount of moisture required in the air.
• Be aware that pressure reducers and valves can also discharge particles.
• Determine the type of pipes used in the plant

Solutions

The solution depends if the compressed air is in contact with the food product or not.

Contact Application Solutions

Contact application is when the air is used for moving, packaging and transportation of food production. The pressurized air in direct contact with the product needs to be purified to a higher standard than for non-contact applications usually to the -40 oF (-40 oC) dew point, with oil free air and very fine filtration to keep out particulate. Methods to achieve this include:

• Absorption-type compressed air dryers located in the compressor room (centralized air treatment).
• Point-of-use air dryers may be of either desiccant (adsorption) or membrane-type technology.
• Coalescing filters remove solid particulates and total oil (aerosol + vapor).
• Activated carbon filters remove oil vapors.
• De-centralized filtration may be needed in addition to the centralized filtration system.

Engineered nozzles and air knives are used to blow off on a product or packaging while conserving compressed air use by using the Coandă effect to entrain surrounding air along with the compressed air.  These products create high velocity, flow and energy air stream. The applications for these compressed air products include:

• Blow off water after washing a product prior to packaging
• Bottling operations to blow off water, especially under “caps” to avoid subsequent problem in potential corrosion issues
• Blow off excess sugar from muffins prior to oven to avoid burnt product
• Cool a product prior to packaging to increase line speed and shorten conveyor length

The Nex Flow Ring Vac compressed air operated conveyor (available in stainless steel and anodized aluminum) are ideal use in food industries. These systems are pneumatic conveying units with no moving parts. They are used to convey solid material at high rates and over long distances, such as:

• Convey bottle caps into a hopper for the bottling line.  Rather than manually loading caps from smaller boxes, larger containers, which are less costly may be used and then the Ring Vac can be utilized to transfer the caps into the hopper.
• Convey solid food items in food blending operations. One specific application was at a company in SE Asia mixing powders for producing a special food spice. Stainless steel Ring Vacs were welding in line and used to transfer various spices from one place into a mixing tank.

Non-Contact Application Solutions

Non-contact application of compressed air in food production includes expelling air into the atmosphere near food preparation, packaging, storing, or conveying. Blow off is used to clean the packaging prior to filling but if there is a time delay after cleaning, there is a greater risk for contamination including oil, moisture, bacteria, and particulates landing on the product or the container. About 50% of compressed air use in food production facilities will have no contact with food products or packaging, so lower cost methods that treat compressed are acceptable. These solutions include:

• Refrigerated compressed air dryers
• Desiccant air dryers
• Coalescing filters are required to remove solid particles and oil (aerosol and vapor) to the same levels required for contact applications
• Activated carbon filters can be used to remove oil vapors
• Centralized or decentralized filtration depending on the food production facility.

General Solutions for Food Production

This is an incomplete list of possible solutions to meet air quality standards in food production environments:

• Guidelines set out by ISO 8573.1:2010, British Retail Consortium (BRC), and British Compressed Air Society (BCAS) specify that air quality should be tested and verified twice per year or per the manufacturer’s recommendations.
• Monitor equipment for particles, moisture, and oil contaminants
• Install and use oil free compressors and use equipment that is most efficient in your plant
• Use only stainless steel or aluminum pipes, which do not corrode
• Reduce relative humidity in the factory
• Use refrigerated air to remove water, then heat the air to room temperature so that the resulting air is low in humidity and bacterial growth

NOTE: When attached to an oiled pipe – the regulations do not state that the air needs to be tested.  

Once the food surface is cleaned, it must be blown with compressed air to ensure no particles are on it.

Refer to ISO 8573 Class 1 or 2 requirements for more information. There is no single solution for all factories when considering the dew point and moisture air management.  Dew points of the air at line pressure must be under minus 15 oF (-26 oC) to inhibit growth of microorganisms and fungi.

NOTE: The dew point is the temperature at which air is so saturated with water vapor that when further cooled – the vapor will condense into water droplets (dew).

When using compressed air to blow out bottles prior to inserting liquids for consumption, the most stringent air standards is not necessary because of the expense or the difficulty to regularly test the air quality. In this situation, it is recommended a point of use filter is installed since 1% of the factory uses very high-quality air for specific applications. The rest of the factory does not need high quality air.  A point-of-use filter is the cheapest and most efficient solution for greater production.

FEATURED PRODUCTS

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Air Quality Testing Strategies

Assessing the food production system’s controls is a customized activity. Keep in mind that compressed air systems are not static. They are dynamic systems because parts breakdown or malfunction, which requires maintenance.  Air quality testing is critical to sanitation in the food industry. Although standards are not completely in place, the desire to protect consumers is enough to establish regular air testing. Before starting an air quality testing program, determine the following:

• Schedule routine testing for OSHA, FDA, and Current Good Manufacturing Practices (cGMP) verification and compliance at each facility
• Determine the particulate control level required for your environment: size and count.
• Determine the air testing equipment required with sampling media
• Know the type of oil present in the factory so the type of tube required for testing can be determined.

The testing programs should produce valid, repeatable testing results that reinforce the site’s air quality. Sampling strategies must ensure that air provided to all food production areas has consistent quality. Sampling options include:

• Determine the percentage of sampling points to be tested over time: 25%, 50%, or 100%
• Consider taking three samples: close to the compressor, midway through the process, and far away from purification as possible.
• Sample before and after the filter is changed. Data collected after 3 to 4 filter changes is useful for determining trend analysis.Monitoring of air quality can be done by either testing all critical points of application or randomly testing a representative portion. Although testing all critical points is expensive, it is the most accurate. Contamination can occur at any specific location without affecting other areas in the same plant. Results could later show that the one area not tested was contaminated.  Additional testing should be performed after maintenance work is performed on the compressed air system. When maintenance is performed, a sample of air outlets shall be tested to ensure that the quality of the compressed air meets the relevant Purity Classes.

The following is a list of some types of air quality tests:

• Laser particle counter
• Filter collection with microscopy
• Solid Particle content by Mass concentration per ISO 8573-8:2004

When collecting samples, ensure that the collection process does not introduce contaminants. Make sure that the sampling equipment is short, straight and made of stainless steel. Any dead ends or bends in the sampling equipment may cause bacterial growth if not cleaned adequately. Straight sampling equipment is important because it will prevent trapping particles before they are sampled.

After the test results are received, ensure that the results fall within the acceptable thresholds by the standards listed in Table 1.  Ensure that the controls you have in place are maintained by routine air quality testing. If the tests results show contamination in the plant, then either reassess the limits that were set to see if they were inappropriate for the application or add controls to the existing compressed air equipment. Additional controls could include additional filters or a refrigerant dryer where there are none. Although testing could be expensive, it is the best safeguard against damage or harm.

Should I use a Mist Cooling System or go the route of Dry Machining to replace Flood Coolant?

Machine operations still commonly use flood coolant but are working on ways to replace with alternate systems.   One such system called Minimum Quantity Lubrication (MQL) attempts to reduce flood cooling.  MQL eliminates conventional flood coolant from the machining processes, lubricating cutting tools with a fine spray of oil directed exactly when and where it is needed. MQL reduces oil mist generation; biological contamination of coolant; waste water volume; costs for capital equipment; and regulatory permitting. MQL also improves recycling and transport of coolant contaminated chips.   Dry machining is also a growing trend when possible to use and is much less messy than mist cooling systems.

Dry machining has been called the machining of the future and there are many benefits to avoid the use of flood coolant, the most obvious being the increasing environmental considerations and the disposal of waste coolant. (Reference: https://www.theengineer.co.uk/the-benefits-of-dry-machining, Oct 4, 2016).    The advantages of cooling, especially to eliminate micro-carbon cracking on carbide tools, are not only for cooling but also to wash out chips from the drilling operations.  Machine designs are now taking these things into consideration as the move to dry machining continues, especially as the growth of new composite materials are adopted.

Nex Flow^® has developed two products to address dry machining applications – one completely dry and another adapting mist for lubrication.

While obviously using a liquid to cool is easier, compressed air can also be used by adopting vortex tube technology such as that used with our Tool Cooler.  A vortex tube takes compressed air and divides the air into a hot and a cold stream – capable of producing very cold temperatures.   Normally the temperatures are 0 degrees C. to 5 degrees C. at the exit to avoid condensation.   The cold air blows directly onto the desired tool.   In many cutting applications this can actually make for a better quality cut.   Applications where the vortex tube alone (usually packed in the form of a tool cooler with a mounting magnet to attach to the machine) complete with a flexible hose to deliver the cold air produced, is ideal for cutting, drilling, milling, routing of plastics, glass, and ceramics.  Titanium steel is another good application for this totally dry cooling system.

In many situations however, some lubrication is required – for example in deep hole drilling.  Without some form of lubrication, the drill can bind.  For this purpose, when attempting to eliminate flood cooling, mist cooling has been used where a “mist” is sprayed onto the cutting operation.  Nex Flow^® has developed a patented system to utilize a vortex tube to cool a lubricating mist which is syphoned up into the unit using a special nozzle.   This is their Frigid-X^® Sub-Zero Vortex^® Mist Cooling System.

As the lubricant is syphoned up, the cold air from the vortex tube cools the lubricant to about 5 degrees C.   Then the cooled lubricant is misted onto the cutting tool with volume controllable by an adjusting knob.  The liquid being cooled reduces the amount of lubricant needed significantly, up to 20% less than what would be needed with a standard mist coolant.  This reduces the environmental effect dramatically, reduces lubricant cost and cools the operation significantly.

The compressed air required for purely dry machining using vortex tube technology is about double that required for using some liquid along with the vortex tube.  In both situations it is important that the compressed air is properly filtered to keep the system clean and dry to prevent condensation and any oil clogging up the vortex tube component.  Recommendation for filters is a minimum 10 micron water removal filter and if there is oil in the air line, a 0.3 micron oil removing filter.  Without proper filtration the systems can be damaged over time and lose effectiveness.

There was a very interesting application recently on board an oil rig where either a Tool Cooler or a Sub-Zero Vortex^® Mist Cooler could be used for a particular cutting application.  The restriction was that the temperature produced by cutting metal was to be kept under 200 degrees C. due to the nature of the explosion proof rated environment.  This could be accomplished by using either system.  Lubrication was not an issue so water was used in the Mist Cooler in lieu of any lubricant.  In addition, the use of water itself was not an issue for the materials being machined.  Both systems were tested.

Both the systems were highly successful in achieving the goal of maintaining any temperature from the operation below 200 degree C limit.  In the end, the Mist Cooler was used because of limited compressed air available for the multiple number of systems required.

In most situations, when moving away from flood coolant it comes down primarily to the need for any lubrication in the process.  If no lubrication is required, for both reasons of eliminating lubricant cost and a cleaner environment in the workplace, it would be best to use purely dry machining process.  However, for dry machining system with multiple stations, care should be taken to ensure adequate amount of compressed air capacity when using a system like the Tool Cooler.   MQL systems are certainly an ideal goal to reduce flood cooling when lubrication is also necessary.  When using the vortex tube operated mist system the lubricant should be water based and after use, be thoroughly flushed from the system to keep it clear and clean for the next use.   Misting however does effect the nearby environment so reducing the amount of liquid is always a plus.  Systems like the our mist cooling system can reduce lubricant use (and cost) up to 20% by cooling the mist as it is being used.

Regardless of which system is chosen, anything to reduce and replace flood cooling offer benefits to both the owners and employees of any company both in cost and environmental impact.

An air wipe is a blow off product used to dry, cool, and clean an extruded product or any other piece that is fed through the unit.  The Nex Flow® Ring Blade® air wipe is compressed air operated and designed such that the compressed air exits the unit over a series of Coanda angles, which entrain a large amount of atmospheric air that mixes with the exiting compressed air, thereby amplifying the air flow at a high velocity to blow off liquid and dirt from the surface of the part being fed through the unit. The Coanda effect essentially converts what is normally lost as pressure drop into flow.  This also reduces exhaust noise dramatically.   Air wipes normally come in “split mode” which means they actually consists of two pieces held together by some means but perfectly matched so each section covers 180 degrees for blow off.  Together they form a 360 degree blow off system. The air is typically directed at an angle to be able to shear off the liquid or other material on the surface of the parts to be cleaned. The Ring Blade® air wipe has the air exiting at a 30 degree angle to the direction of flow of the part that is fed through the system.  This gives it the most ideal shearing angle to clean and dry. The part being fed through does not have to be perfectly smooth nor even cylindrical – it can be quite a complex shape (which is true with automotive EPDM profiles for example) and still be dried very well as long as the air hits the surface.   

Some common uses for drying extruded items include:

• Wire
• Cable
• Window Profiles
• Automotive EPDM trim
• Rope

Other uses are for cleaning tooling manufactured that is fed through the device to be cleaned and dried, and steel pipe being manufactured and fed through the system – basically anything that would fit through the unit.

One rule that is important is to have the part that is fed through the air wipe to be as close to the wall of the system as much as possible without touching the wall.  Ring Blade® units for example come in various standard sizes with an inside diameter of ½”, 1”, 2”, 3”, 4”, 5”, 6”, 7”, 9” and 11”.   Special sizes such as 1-1/2” have been produced as well. The further the piece is from the insides wall of the air wipe, the lower the force.  So if the part to be dried is – for example – a 1-3/4” X 1-1/2”rectangular shape you would feed it through a 2” Ring Blade® air wipe and not through a 6” unit. Also, it would make sense to keep the unit as small as possible as air consumption goes up with the increase in size.   Having said that, if the product is moving slowly through the system, you can often go a size larger. If going at high speeds however, you generally need to have the walls closer to the piece being cleaned or dried.

One way to deal with very fast speeds through the Ring Blade® air wipe is to open the air gap with an extra shim that maintains the air exit size.  This can also make it possible to clean and dry small sizes through a larger internal diameter systems.  However, this does increase compressed air consumption. For very high speeds it is preferable to have a second unit downstream the first one for secondary application.  It should be downstream far enough so the he air from one unit does not interfere with the air flow of the second.

A question sometimes comes up is whether an air wipe can be held hand.  It would most likely be very difficult to hold by hand larger diameters but for smaller ones this can be done.    For example, if there are many pieces that can fit through an air wipe, but for some reason are not able to be fed through a system, then these pieces can be placed vertically on a table (or floor) and the air wipe passed over and down through these pieces to dry and clean.  The blow off force will be such that you need a good grip when using it this way, but not impossible to do so. Some items which need cleaning or drying, that are now cleaned or dried with air guns might be suitably shaped where an air wipe can be used to do the job faster and easier.   This is because an air gun does not give the coverage and therefore the person handling the unit has to do a great deal more movement.    If the shape can be put through the system, it can be used manually. However, if there are enough parts, it is usually more economical to set up a feeding system.

The Nex Flow® Ring Blade® air wipe is very similar to the Nex Flow®  Standard Air Blade® air knife.  In the Standard Air Blade® air knife the compressed air exits a gap in the air knife and goes over a series of Coanda angles that bend the air and entrain the surrounding atmospheric air to amplify the air flow.  The air wipe is basically this same design curved and then altered so that the 360 degree flow exits at a 30 degree angle to have the high velocity air produced converge at some point away from the unit.  This provides an ideal shearing force against any part that enters the air wipe so get into crevices and corners of odd shaped parts to be able to clean, dry and cool. Special systems have been made as one piece systems and even at special shearing angles per customer requests and special applications.  However, the normal units are supplied as two 180 degree pieces joined together by hinged units to easily “open” them. The reason is that most applications are from extruded parts. Some of these extruded parts such as EPDM rubber profiles on startup form a big bubble that is larger than the normal dimensions.  This allows the air wipe to be “opened” to feed the bubble through as the extrusion proves begins. Similarly it is in two pieces to address knot in wire drawing and other possible applications where such bubbles or material buildup needs to be dealt with, without cutting into a continuous extruded line.

While Nex Flow®  manufactures units up to quite a large diameter (11”), to go any larger can be a manufacturing challenge.  But, as the diameter or shape that needs to be addressed becomes larger, it can often be easily addressed with a ring of Air Blade® air knives instead because the larger the part, even a round shape like a pipe approaches that of a relatively flat but curved surface.  This is why air knives can just as easily address those large parts. But when the part is smaller, (and generally moving at very high speeds as well), the air wipes can do a much better job of drying, cleaning and cooling.

Air wipes are quiet, have low air consumption, have uniform airflow across the entire diameter, have no moving parts, use no electricity, compact and easy to install.  They are non-contact drying/cleaning devices.

The material of construction can be important.   The Nex Flow® Ring Blade® air wipe comes in three standard material constructions: aluminum body with a stainless steel shim set to maintain the air exit gap, brass fittings and a strengthened rubber hose to connect the two haves for one air inlet (sizes larger than 7” diameter do not have a connecting hose and air must be fed separately into each half section).   This construction is suitable for most applications in regular factory environments and when subjected to temperatures below 150 degrees F or 66 degrees C.

When dealing with higher temperatures up to 400 degrees F (204 degrees C), the rubber connecting hose is replaced with a stainless steel connecting hose.

If subjecting the air wipe to a corrosive and/or a high temperature environment up to 800 degrees F (427 degrees C), the body is made of 316L stainless steel, with 316L stainless steel shims, and 316 stainless steel hose and fittings.   

One final note is that the compressed air supplied to the product should be clean and dry.   A minimum of 10 micron filtration is recommended for water removal from the compressed air lines and if oil can be an issue, an oil removal filter of around 0.3 micron filtration is recommended.  Should the compressed air lines have significant issues of compressed air cleanliness, some options are the Nex Flow® filter or the Super Separator.   These quality filtration products operate with no replaceable cartridges and can address such air cleanliness problems.

When choosing a compressed air operated air wipe, recognize the need to keeping the internal diameter of the unit close to the part being fed through the unit, consider the speed of the material being fed through the device, and determine the material needed for the environment in which the unit is being subjected.  Plus assure that the supply air is clean with an adequately large airline size to avoid pressure drop. In this way you will have a trouble free, near zero maintenance device to dry, clean and cool the product being put through the system.

Compressed air can be costly – so it is important to keep waste at a minimum while taking advantage of the benefits compressed air offers.

A good practice is to measure and monitor your compressed air system, flow rates, operating air pressure and energy consumption. Small adjustments where applicable can reduce your operating costs while improving flow rates and output. Here are 10 things that you can do now to optimize your systems and reduce energy costs!

1.When Not In Use, Turn Off the Compressed Air.

There are 168 hours in a week, but most compressed air systems only run at or near full capacity between 60-100 hours. So depending on your plant’s shift work pattern, you may consider turning off your compressors in the evenings and on weekends.  This could reduce your energy bills up to 20 percent!   One of the advantages of compressed air is that the energy can be used “on demand” so you can use it only when you need and not when you don’t.  For example, if you are using compressed air for any blow off, drying or cooling application and the part being addressed is intermittent, you can install a sensor, PLC or timer and a solenoid valve to turn the compressor on and off as needed.  Depending on how intermittently the air is needed, savings can easily add up from anywhere between 5% and 20%.   This is an advantage of compressed air that is often overlooked – so when using compressed air, or considering its use against other options, don’t forget to keep the actual cycle time in mind because this can have dramatic impact on the actual costs. You cannot have this instant “demand” with most other options.

2.Find and Fix Existing Leaks in the System.

An air leak that is ¼” can cost you more than $2,500 a year.  Imagine a series of smaller leaks that can potentially add up to sizes larger than ¼”. Pipe systems that are older than five years may have leaks of up to 25 percent of produced capacity if left unchecked and unrepaired. It takes energy to generate compressed air, so any air that leaks is essentially money wasted. Yet – air leaks tend to be largely ignored because you cannot “see it”. But if you have a water leak it is readily visible and often quickly addressed. Yet the cost of a compressed air leak can be much higher. Approximately 80 percent of air leaks are not audible so one means to detect (and then repair) leaks is to regularly check for leaks using a quality Ultrasonic Leak Detector.  Many air leaks are from piping (especially at pipe joints), and from poor, inexpensive or worn out fittings, from valve assemblies and even from stuck auto drains used on filters.  To minimize these problems, sometimes third-party is contracted to come into an operation to detect these leaks, assess their cost and the factory can then facilitate appropriate repairs or part replacements as necessary.

3.Prevention of New Leaks.

Benjamin Franklin once said, “An ounce of prevention is worth a pound of cure.” Check your piping system for its quality. A clean, dry pipe system indicates good quality compressed air and no corrosion issues. Dust in the pipe is caused by particles in the compressed air. If the air is not properly filtered, or if inlet filters are clogged, pressure drops will occur and the risk of end product contamination will increase. Sludge in the pipe is very bad news and should be addressed immediately. Dust and sludge in a compressed air piping system will cause corrosion very quickly and will greatly increase the number of leaks. Properly dried and filtered air keeps your pipe system clean and minimizes the occurrence of leaks.  Be proactive in regularly checking for leaks in filters, fittings, valves, and connectors.  Old quick disconnects are notorious for leaks. Use quality units and replace worn out units.

4.Reduce System Pressure if Possible. Run at required pressures – not more, for Each Application.

Every two PSIG reduction in compressed air pressure from the air compressor reduces energy consumption by one percent. When a system has issues there is a tendency to increase the supply pressure to compensate.   Leaks cause pressure reduction downstream so resist the urge to turn up the pressure to compensate for leaks.  Pressure drop is also caused by undersized piping delivering the compressed air to specific applications or by undersized fittings, and connections or from clogged filters. It is better to address the actual cause or causes of the pressure drop rather than simply increasing the supply pressure.  A central supply side controller can reduce the operational pressure band and control air production more efficiently and effectively.  Pressure regulators with gauges at appropriate locations can set the optimal pressure level needed for the particular application to minimize compressed air use and also indicate when access pressure drops occur.

5.Check Condensate Drains. Are your condensate drains stuck on open?

Condensate drains on timers are common items and there is a perception that they do not waste a great deal of compressed air.  They should be adjusted periodically to ensure that they open as intended and that they do not get stuck in an open position. Concerning the perception that timer drains waste only a small amount of compressed air, it may be true in a small operation.  However, if you have more than a few such units, that small cost can add up to a significant amount.  It is better to replace timer drains with zero-loss drains to stop wasting compressed air.   Such drains used to be expensive but have come down in cost significantly over the years and are now much more economical to use.

6.Review Your Piping Infrastructure to Optimize.

A piping system design should optimize transfer of compressed air at the desired flow and pressure to the point of use. Increasing the size of a pipe from two to three inches can reduce pressure drop up to 50 percent. Shortening the distance air has to travel can further reduce pressure drops by about 20-40 percent.  Factory operations change over time. Machines are moved, added, or replaced.  A look at the system pipe size and layout to determine how much compressed air is used in each section can provide an idea of whether the pipe is at the optimum size for current use. The more flow through a pipe the greater the pressure drop. The drop also increases with the square of the increase in flow, which means, if you double the flow, the pressure drop will increase four times. Air distribution piping diameter should be large enough to minimize pressure drop.  If the piping is too small, it should either be replaced or a parallel line should be installed. Either option can address the issue.

7.Change Filters Systematically. Not only when they become so clogged that you must change or service them.

Inspect and replace or service filters systematically to ensure the quality of your air and prevent pressure drops. Over time, filters with replaceable cartridges will build up particulate on the cartridge and this increases pressure drop.   In some cases indicators are available (pressure gauges before and after the filter also do this) to indicate the pressure drop across the unit. This goes beyond just the air compressor and the compressor room. All air-line and point-of-use filters within the facility should be checked and a regular cartridge replacement or filter cleaning schedule should be put in place depending on the type of filters. Those are just as important to maintain as the air compressor and air compressor room filters.

8.Utilize the Heat of Compression. Compressing air generates heat – Use it!

When compressing air it gives off heat, a lot of heat.  As much as 90 percent of that heat can be recovered for use in your factory operations with heat exchanger technology. This wasted heat can be used to produce hot water for washrooms or to warm up and direct warmed air into a workspace, warehouse, loading dock, or entryway. The savings can be significant.  This alone can justify using compressed air over other power sources if this waste heat has a useful purpose.

9.Follow Your Compressor Maintenance Schedule. Ignoring maintenance costs more.

You would not ignore a scheduled oil change on your car.  The same reasoning applies here.  As with most industrial machinery, in fact any machinery, a compressor runs more efficiently when properly maintained. Proper compressor maintenance cuts energy costs around one percent and helps prevent breakdowns that result in downtime and lost production.  Maintain oil change schedules and other timely scheduled maintenance on your compressors.  If you have several compressors consult your air compressor supplier on the most efficient way to have them set up to run and review the types of compressors best suitable for your current applications.

10.Use Directed Compressed Air More Effectively.

.About 70% of compressed air products (after leaks) is used for blow off and cooling. Inappropriate applications includes any application that can be done more effectively or more efficiently by other means than using compressed air such as blowers. That being said, however, compressed air is often used because of the velocity or force necessary for certain application that blowers cannot provide. At other times the cooling effect is desired where other options cannot do for any number of reasons, some being available space or lack of local support for another technology.  Rather than demonize the use of compressed air, it can be applied very efficiently for blow off, drying and cleaning by using engineered parts like air nozzles, and other air “amplifiers” both annular type and linear or “air knife” versions that converts energy normally lost as pressure drop and noise into high velocity and high volume flow.   This type of technology can reduce compressed air costs at point of use anywhere from 10% to 90% while maintaining production rate output and quality, something which is sometimes sacrificed when attempting to replace compressed air. Therefore it is wise to thoroughly consider the benefits and drawbacks of your options before making a decision.

So that’s 10 ways you can reduce and save up on compressed air use and energy for your plant. Don’t forget to think of the benefits and drawbacks when choosing a product for your specific application and be creative! Even heat that is normally considered a waste product can be utilized to save operation costs!

What are Air Amplifiers, Jets, and Knives?

Air Amplifier

There are two types of Air Amplifiers – Air Pressure Amplifiers and Air Volume Amplifiers.   This article talks about volume amplifiers, which harness the energy from a small parcel of compressed air to produce high velocity and volume, low pressure air flow as the output. It can amplify the volume up to 17 times the air consumed.

The volume amplifier uses an aerodynamic effect called “the Coandă effect”. One example of this effect is seen on the Coandă angles on airplane’s wing that can cause the airplane to lift. In an airflow amplifier, the force is directed outward to cool or dry a surface. Pressure normally lost as noise and is converted into amplified and high velocity laminar flow.  

Compressed air stream flows through an air inlet, clinging to the “Coandă” profile inside. The compressed air is throttled through a small ring nozzle at high velocity and guided towards the outlet. This results in a low-pressure area at the center, inducing a high volume of surrounding air flow to the airstream.  Airflow is further amplified downstream by entraining additional air from the surroundings at the exit. This adds further volume and flow to the primary airstream via a similar method. The combined flow of primary and surrounding air exhausts from the Air Amplifier is a high volume, high velocity flow.

The jets of air in the amplifiers create a high velocity flow across the entire cross-sectional area, which pulls in large amounts surrounding air, resulting in the amplified outlet flow.  

Note: Air Amplification Ratio is the ratio of the air flow in standard cubic feet/minute (SCFM) or standard liters per minute (SLPM) at the exit point divided by compressed air consumption with the same unit. This ratio can vary with inlet pressure and temperature as well as the density of the inlet air, so the figure provided is a weighted average. The ratio may be reduced if any back pressure is put on the amplifier exit or suction end by attaching a hose, pipe or tubing

There is a balanced between amplified air flow and air velocity. Any air amplification ratio higher than 17 will slow the velocity so much that the blow off force becomes ineffective and the cooling effect lost.

NOTE: It is recommended to regulate the compressed air supply so the very least amount of air necessary is used.  Install a solenoid valve on the compressed air supply side to turn the air off when the air amplifier is not in service.

Air Jet

Air Jets are either annular like Air Amplifiers or in a flat design (air edger).  Due to their size and “Coanda profile”, annular Air Jets provide a greater concentrated force using amplified air.  This makes them ideal for applications like part ejection. Nex Flow Flat air jets or Flat Jet Nozzles are a compressed air operated chamber of shorter length than an air knife with a higher force and flow design. The internal chamber and outside shape are designed to minimize pressure drop and convert this into flow and force.

Flat Air Jet Nozzle (Air Edger®) is used when a much stronger forced air is required than an air knife can provide.  The flat jet nozzle can be mounted on manifolds of different lengths (holding 2, 4, or 6 units typically and more). Like an air knife – shims can be added to produce higher force. Due to the chamber design that is quite different from an air knife – a greater range of shims can be added to the flat nozzle allowing it to produce much higher air force than an air knife is able to provide.

The Air Edger® Flat Jet is available with various size “gaps” all set with a flat stainless steel shim. Three standard shim sizes are available – .004” (.10 mm), .008” (.2mm) and .020” (.51 mm). Shims can be “stacked” for a larger gap and greater force up to a maximum gap of .024” (61 mm).

Air Knife

An air knife is positive pressurized air chamber that contains a series of holes or continuous slot through which a predetermined air volume and velocity exits. The air is blasted through the air chamber using an air compressor or industrial blower. The air knife is typically made from either aluminum or stainless steel of various lengths but can be made of other materials as well.

Note:  Electrical currents from anti-static bars can also be injected into the air knife air stream to neutralize the static electricity charge on some surfaces.

Things to consider when choosing an air knife includes:

• Force required
• Material: typically aluminum, stainless steel, and special plastics
• Required Length or distance from the compressed air source to the target.
• Installation Cost
• Noise
• Air Consumption

Applications of Amplifier, Jets and Knives

Air Amplifier

There are many different applications for air amplifiers to completely list – but main applications include blow off, cooling, and ventilation:

• Blow off:
  • Purging tanks
  • Used in ventilation of fumes, smoke, lightweight materials from automobiles, welding, truck repair, plating or holding tank or other confined spaces.
  • Circulate and blow off air
• Cool hot parts: Cooling dies and molds
• Dry wet parts
• Clean machined parts:
  • Vacuum device to clean machined parts and confined places: dust collection, remove metal chips and scrap, collect and move dust (grain operations)
  • Clean a conveyor belt or web
• Convey:
  • Used to convey small parts, pellets, powders, and dust.
  • Exhaust tank fumes; Used to remove fumes quickly and efficiently for venting applications. The fumes can be ducted away, up to 50 feet (15.24 m), and the amount of suction and flow is easily controlled.
  • Moves air 12 to 20-fold in duct applications and up to 60 times in areas with no ducts.
  • Component removal, valve gates, and automated equipment for ejection molding systems
  • Distribute heat in molds/ovens
  • Sort objects by weight
• Used as tools in production lines, wood working, aerospace, construction, dentistry, heath care and hospitals
• Used in assembly, chemical processing, robotic cells, and chemical processing
• Increasing existing plant air pressures
• Used in medical, food, and pharmaceutical installations
• Used in Pneumonic cylinders: Enhances efficiency of pneumonic tools and machinery
• Bottle molding applications
• To enhance the “WOW!” factor of amusement rides in certain thrill rides; such as roller coasters
• Coat a surface with atomized mist of liquid
• Activating adhesives and heating-shrinking: High air amplification puts much more airflow through the heater coils than would be possible with an ordinary fan or blower. The hot airstream can be felt over 10′ (3m) away!

Based on Type, Size, and Material:

1. Available 0.002 and 0.003” shims can be added
2. Gap setting from 0.001” to 0.004” to control the output flow and force required.

Special plastic versions are used to cool materials in an electrical power grid where metals can not be used. Alternative materials can be machined to be used as an air amplifier unit in corrosive environments where stainless steel is not sufficient.

Nex Flow manufactures special Air Amplifiers to your specification including special flanged mounting style or with a PTFE plug to avoid sticky material build up.

Benefits to Using Air Amplifiers: For air amplifiers, the outlet flow remains balanced and minimizes wind shear, sound levels are typically three times lower than other types of air movers. Both the vacuum and discharge end of the Air amplifier can be ducted, making them ideal for drawing fresh air from another location or moving smoke and fumes away. They are ideal for increasing existing plant air volume for blowing or cooling and for venting.

• Compact, lightweight, portable
• No electricity
• No moving parts – no maintenance
• Ends are easily ducted
• Instant on/off
• Longer life in difficult environments than competitive models.
• Lower compressed air consumption than ejectors and venturi.
• Maintenance free with output easily controlled, safe to use.

Air Jet

Flat jet air nozzles are used for a concentrated and targeted application of air and other gases. They are used to provide a powerful stream of high velocity laminar flow and high force for blow off and cooling applications where air knives are not sufficient.

Annular Air Jets entrain large volumes of surrounding air through the Jet (like Air Amplifiers) and are more efficient flow amplifiers than Air Nozzles. They cover a larger blow off target than a Nozzle and are ideal for part ejection. An air nozzle provides a point force, while the Air Jet acts more like a “hand” and covers a larger area in blow off coverage.  This can be an advantage in part ejection where two nozzles are normally required to “direct” the ejected part while only one jet is needed.  This can dramatically reduce energy required as well as have a lower footprint on the machine.

Applications of an air jet:

• Part cleaning
• Chip removal
• Part drying
• Part ejection
• Air assist
• For moving heavier material that requires extra force to move.

Benefits to using an Air Jet: Air consumption and noise levels are minimized with its special design and configuration while providing a strong blow off force.

• Reduced compressed air cost
• 10 dBA average noise reduction
• Conserve compressed air
• Compact
• Improved safety
• Meets OSHA noise level requirements
• Improved production

Air Knife

An air knife is used to create an air curtain to clean, dry, or cool a surface of a product without mechanical contact.  In most cases, the air knives are stationary while the products that are cleaned or cooled are traveling on conveyors. In other manufacturing applications, the air knife moves or rotates over the surface of the stationary product. In rare circumstances, an air knife can be used to cut products. One such example in the food industry is by using an air knife to cut into cake frosting.

The following is a comprehensive list of air knife applications using compressed air:

• An air knife is used to blow off a curved or flat surface of unwanted liquid (such as water), grime, airborne debris, dirt, or dust from surfaces or objects using a high-intensity, uniform sheet of amplified airflow.
• Air knives are a good cooling tool.
• They are also used to control the thickness of liquids
• Used in food, pharmaceutical, packaging, automotive, mining, heavy industries (steel and aluminum), and circuit board manufacturing, and printing
• Used the first step in recycling to separate lighter particles from other components.
• Used in post manufacturing of parts for drying, conveyor component cleaning, and to draw in waste fumes or exhaust.  
• Create an invisible air barrier to separate heated or cooled environments from one another in industrial applications such as continuous metal heat treating ovens, cold process or storage areas in food processing or dust containment for the entrance to clean rooms.
• Removal of excess oils, liquids, and dust from flat and curved surfaces
• Part Drying after wash
• Conveyor cleaning
• Component or Parts Cooling
• Drying or Cleaning of Moving Webs
• Environmental Separation (air barriers)
• Blow off in pre-paint systems
• Bag opening in filling applications
• Scrap Removal in converting operations

Benefits to Using compressed air – air knife: Compressed air operated air knives are more compact in design, easier to control, and far less noisy than blower operated units.  

• Quiet – 69 dBA for most applications
• Uniform airflow across entire length
• Minimal Air Consumption
• High Force/Air Consumption Ratio
• Variable force and flow
• No moving parts – maintenance free
• Easy mounting
• Compact, rugged, easy to install
• Stainless steel screws in all models
• Standard Units 30:1 air amplification
• X-Stream Units 40:1 air amplification
• X-Steam Units can do the same job as competition at lower pressures
• Materials Anodized Aluminum, Hard Anodized Aluminum, 303/304 stainless steel and 316L stainless steel
• Stainless Steel shim
• Special Lengths Available

Blower operated systems are advertised as being more energy efficient but that is not always the case.  In intermittent blowing and lower pressure applications, compressed air knives can be as energy efficient as blower operated systems.  

Compressed air operated air knives have smaller/more compact dimensions, more rugged, quieter, and do not have the costly maintenance compared with blowers, making compressed air operated systems the smart choice especially when space is a premium. A compressed air operated air knife provides significantly more force than a typical blower.

Air knives are ideal for liquid and dust blow off. Air knives provide clean, heated air; low operating noise (even without sound enclosures); and easy installation and operation.

Drawbacks to Using Compressed air – Air knife: Not good for heavier material that needs to be removed. In this case, choose an air jet.

Conclusion

Compressed air operated Air Amplifiers, Jets, and Knives are effective tools for your manufacturing environment.  It is critical to know the requirements of your application to choose the correct product. Experts at Nex Flow are happy to assist you in choosing your compressed air solution for your manufacturing application.

What causes static charges and why control it?

Active vs. Passive Static Eliminator

Plastics, glass and other insulating materials generate a static charge when rubbed, cut, and stretched.  Hot or warm plastics will generate a static charge as they cool. In many production processes this can cause any of the following problems:

1. Static charge will attract dirt particles. If the part needs to stay clean for further processing such as painting, coating or even just packaging, these particulates can be a major issue.
2. As the product moves along the manufacturing process, materials such as film may bend or warp due to static and cause jamming of machinery, and hence downtime.
3. If the static charge is high enough, it can cause sparks and discomfort or even harm to personnel working with the material that is statically charged.

For these reasons, static charge needs to be eliminated or at least reduced and controlled. So how does the static charge get generated in the first place? Static electricity is the result of an imbalance between negative and positive charges in an object. These charges can build up on the surface of an object until they find a way to be released or discharged.

The rubbing of certain materials against one another can transfer negative charges, or electrons. For example, if you rub your shoe on the carpet, your body collects extra electrons. The electrons cling to your body until they can be released. As you reach and touch your pet (which is being really mean!) or perhaps a door knob, you get a shock. This same process occurs in a production line.

There are two ways to address a static charge. One is with a passive static eliminator and the other is with an active static eliminator.

Passive Static Eliminator

Some Passive static eliminator examples include: Copper Tinsel, Nylon Brushes, Sharp Edged Metal Strips, Antistatic Flexible Rope and Anti-Static Spray. These passive devices usually only reduce the charge with the exception of antistatic spray. In some situations – a reduction in the static charge may be adequate, however there are limitation with these passive devices. For rope and tinsel, it can potentially be dangerous when they break off and also has the potential to fall onto the material being processed. Antistatic spray may not be used if the statically charged part cannot tolerate a liquid for any reason. Brushes are limited to slow moving and lower static charges – most commonly used with printers, fax machines, and elsewhere where static only needs to be reduced to avoid sticking of the sheets.

Using passive static control may help in preventing some machine jamming and address employee discomfort but because it does not eliminate static completely (except for antistatic spray) it will usually not be enough to address dirt problems caused by static. Sprays have the disadvantage of being an endless consumable and an on-going cost that can add up over time. If the charge is very high, a passive device may knock the charge down to an extent but still leave a very high static charge that needs to be further addressed. This is when active static elimination is needed.

Active Static Eliminator

Active static eliminators (static bars or ionizing bars) are electrically operated and can be either AC or DC systems. DC systems are designed to work farther away from the target but are usually more costly than AC systems. On the other hand, AC systems normally work close to the statically charged product to remove the static charges. That being said – a more powerful AC system such as the Haug VS bar offered by Nex Flow is available which works at a further distance depending on the speed of the target. Active systems essentially ionize the oxygen molecules of the surrounding air which get attracted to the charged surface, thereby neutralizing the charge that the air “sees” (come in contact with).

Active systems work by generating alternatively a negative and then a positive charged ion. Whatever the charge on the surface is, the oppositely charged ion will remove it. Active systems can remove almost, if not all the static charge from the surface of a statically charged part. There needs to be an adequate number of ions for the level of charge needed to be addressed as well as some dwell time over the charged area. The faster the target moves the less dwell time is available for the static eliminating ion to remove the static charges. So for fast moving materials, you need a more powerful static bar – either high powered AC system or a powerful DC bar. Keep in mind that the distance from the target also matters. The further the bar is positioned, the longer it takes for the ions produced to arrive at the target and as they travel some will recombine. The result is less concentrated eliminating ions reaching the target surface.

Combining an Air Knife to a Static Bar

One way to help make a static bar work further away is to push the ions with either low pressure compressed air or with blower air. There is a myth perpetrated by some companies that make air knives, claiming that you can remove static charge at a ridiculously large distance just by adding a compressed air operated air knife. This is not entirely accurate. It is true that compressed air operated air knife, being laminar will push the ions and have much less of a recombination of ions than pushing these ions with a turbulent flow, but some recombination will still occur. So the further away the static eliminator bar is placed from a statically charged target, more dwell time will be needed to remove the static charge.

The only way to address a very high static charge or a fast moving target at a great distance from the target is with a stronger static bar that produces more ions – not by just using a compressed air operated air knife. History has proven this. If a static bar works at a moderate distance to the statically charged surface, it will probably still work if the static bar is combined with an air knife, on a moderately charged surface and at moderate speed. But to truly eliminate static charge farther away or at high speed, you actually need a stronger AC bar or a DC bar, with or without an air knife.

The real purpose of an air knife, whether blower operated or compressed air operated is to clean the parts. Dirt particles that stick due to static charge cannot be blown off easily because they get attracted back to the surface, even if loosened by a blast of air. By combining a compressed air knife with a static bar (ion air knife), the ions that get pushed by the laminar air flow eliminate the static charge allowing the static particles to be easily removed. Once the static charge is gone, it takes very little energy to remove the particles, so the air pressure can be as low as 2 – 3 PSIG in many cases. Blowers combined with static bars also work but because of the nature of the air flow with blowers, they need stronger or double static bars to do the same job and should have a high mass flow. In many instances, if the air flow is intermittently used, the energy cost of a compressed air knife static systems to blower air knife static systems are about the same. The advantage of a compressed air versions is that it is much quieter, simpler, compact, and is less costly to install and maintain. Nex Flow offers compressed air operated air knife systems with standard as well as with extra powerful static bars.

Combining an Air Amplifier to a Static Bar

Another version combining compressed air with static control is using an annular compressed air amplifier with a point ionizer (spot ionizer). This produces a laminar cone of ionized compressed air to blow onto the charged surface. Some applications include neutralizing the inside of blow molded or injection molded containers to loosen and remove plastic pieces and strings inside due to cutting processes.  Another application is to blow off plastic strings and pieces after a molding process form the mold itself. Again, all these particles stick due to static charge. Our Ion Blaster Beam is a point ionizer attached to a compressed air amplifier via a plastic attachment. The attachment should be plastic to avoid the grounding effect of metal that would reduce the effectiveness of the ions generated. This is one of the reason why our Ion Blaster Beam works up to 30% faster than competitive units of similar design but with metal attachment.

Manual Static Elimination

For manual static elimination, an anti-static air gun is best and for the same reason stated above.  Dirt particles are not easily removed if they stick to the surface due to static. Only by removing the static charge can a surface be cleaned. As with air knives and with the annular amplifiers combined with a static eliminator, once the air from an anti-static air gun neutralizes the charge on the part, particles can be blown off with minimal pressure and minimal compressed air consumption.

In summary

There are passive and active static control systems. Active static control is the only means to eliminate static charge completely and not adversely affect the end product. If the static elimination system is far from the statically charged target, or if the target is fast moving, or has a very high static charge, you need to use a more powerful static eliminator or increase dwell time.

The main application for using compressed air knives and amplifiers with static eliminators is more so for cleaning the charged surface and less so for pushing the static eliminating ions. That said, compressed air knives and amplifiers with static eliminators can be used at very low pressures and, especially when used with on-off control the energy cost is comparable to using blower systems. The advantage is that compressed air operated static eliminators are low cost, compact, quiet, simple and easy to use with minimal maintenance.

For manual cleaning operations an anti-static air gun is ideal and can save a great deal of energy because you can clean with less pressure than using the air gun solely.

FEATURED PRODUCTS

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Have you ever considered the manufacturing standards required for sterile products such as medication or medical appliances? Food and pharmaceutical manufacturing facilities require higher quality of air because the products are ingested or placed in humans and animals.  The final product must be free of particles, microorganisms, water, and oil. It is the manufacturers responsibility to ensure the quality of the product that is produced.

The possible contaminants in compressed air in a manufacturing environment include: particles, microorganisms, water, and oil.  The air quality is the measure of these contaminants in the compressed air. An official publication, containing a list of medicinal drugs with their effects and directions for their use (called a pharmacopoeia) – have relatively inaccurate qualities compared to the standards required for pharmaceutical water (Requirements for compressed Air in the Pharmaceutical Industry, retrieved November 2, 2018). Since the requirements are inaccurate, mistakes are made, unnecessary expensive and inefficient designs are implemented; specifically, in the following situations:

• sterile compressed air is not a requirement to manufacture all pharmaceutical products or an entire plant.
• oil free compressed air – standards do not set reasonable mg/m3 limits.

In most cases, compressed air contacts the product. As the pharmaceutical industry has grown, so too has the use of compressed air for breathing air, equipment, and instrument air operation.  The USA accounts for about half of the global pharmaceutical market. Each facility has unique needs so different standards apply. The ultimate goals are guaranteeing compliance with standards, levels of safety, and quality set forth by the FDA and other regulatory entities. Many of the standards in the food industry also apply to the pharmaceutical industry as they both pertains to things human may consume.

To apply the appropriate regulatory process to for compressed air and pharmaceutical management systems, it is worth noting the following regulatory organizations and standards:

Sources of Contaminants

The sources of contaminants in compressed air manufacturing environments are:

• Sources of oil that could exceed the 0.1 mg/m3 requirement include:
  • Leakage spray near the air intake of the compressor
  • Emergency diesel generator being tested
  • Traffic jam on a nearby highway.
  • Oil could be hydrocarbons oxidized to CO2, oil aerosols, or vapor, which could reach the compressed air via the compressor.
• Relative Humidity is a source of moisture in the air
• Micron size particles are naturally in the air
• Corrosion particles flake off due to high flow rate.

Impacts of Contaminants

One cubic meter of untreated compressed air may contain close to 200 million dirt particles and other substances like water, oil, lead, cadmium and mercury. The impacts of contaminants in a pharmaceutical plant are:

• Microbial and bacterial growth on products and equipment
• Hazardous consequences to consumer health:
  • Corrosion Particles landing on a sterile implant or medicine.
  • Exposure to or ingestion of hydrocarbons
• Contaminates could accumulate on manufactured products.
• Corrode pipes causing blockages and reduces the life of filters, drains, and machinery in plants.
• Increased energy and cost of operation.

Understanding Air Quality Factors?

The factors that need to be understood in a pharmaceutical manufacturing environment to improve air quality are:

• Understand the impact of air quality on the work zone, workers, and the product or service manufactured.
• Review Direct Product Contact, Indirect Product Contact, USP, and ISO 8573 air standards
• Understand your requirements. Do you need a clean room in your factory? Clean room air quality is expensive to deliver and maintain.
• Identify the current air quality in the non-clean environment.
• Determine the air testing equipment required with sampling media
• Determine the particulate control level required for your environment: size and count
• Engage the production engineers who are most familiar with air quality requirements. They are the resource to determine what needs to be removed from the air and which filter to use for the correct solution. The production engineer would also know the dampness of the air required: moist or dry.
• Determine the amount of moisture required in the air.
• Know the type of oil present in the factory so the type of tube required for testing can be determined.
• Be aware that compressed air pressure reducers and valves can also discharge particles.
• Determine the type of pipes used in the plant

FEATURED PRODUCTS

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Solutions

This is an incomplete list of possible solutions to meet air quality standards in pharmaceutical manufacturing environments:

• Develop, and regularly perform site-specific testing programs to produce valid, repeatable testing results that reinforce the site’s air quality.
• Schedule routine testing for OSHA, FDA, and  Current Good Manufacturing Practices (cGMP) verification and compliance at each facility
• Monitor equipment for particles, moisture, and oil contaminants
• Install and use oil free compressors
• Use only stainless steel or aluminum pipes, which do not corrode
• Monitor your intake air: decrease the RH factor and keep it clean
• Use equipment that is most efficient for your factory.

NOTE: When attached to an oiled pipe – the regulations do not state that the air needs to be tested.  

All factory processes do not require the same air quality standards.  When manufacturing equipment that will enter a person’s body (such as knee and hip joints, defibrillators, and pacemakers), a clean room must be designed that uses a spec that ensures a heightened level of particulate control. Once the surface is clean, it must be blown with compressed air to ensure no particles are on it. Refer to ISO 8573 Class 1 or 2 requirements above for more information. If you are creating a clean room in a non-clean environment – the quality of the extremely clean air – is decreased when introduced to the non-clean environment. If the temperature is too cold, it may destroy the manufactured product by hurting or deactivating them. In other products, the moisture in the air could interact with the material resulting in issues. In these situations, extremely dry air is required.  There is no single solution for all factories when considering the dew point and moisture air management.

NOTE: The dew point is the temperature that air becomes so saturated with water that if cooled further it will condense to form water.

Microbiological limit values are missing for the compressed air both in the pharmacopoeia and in the ISO 8573. The limits based on the clean room classes in which the compressed air is used should be defined, e.g. for class C the max. permissible 100KBE/m³ from Annex 1.

When using compressed air to blow out bottles prior to inserting tablets or to run machinery, the most stringent air standards is not necessary because of the expense or the difficulty to regularly test the air quality. In this situation, it is recommended a point of use filter is installed.  In these cases, 1% of the factory uses very high-quality air for specific applications. The rest of the factory does not need high quality air. A point-of-use filter is the cheapest and most efficient solution for greater production.

Many factories use refrigerated air to remove water, then heat the air to room temperature so that the resulting air is low in humidity and bacterial growth.

Nex Flow works with pharmaceutical manufacturing companies to recommend the right product that complies to operational efficiency and safety.

What is a Vortex Tube?

A durable, stainless steel “Vortex tube” is used to convert compressed air into cold temperatures, as low as -50 oF (- 46 oC) to spot cool as well as to air condition an enclosure. Vortex Tubes are used when other cooling tools are not able to cool an area or an enclosure to the desired temperature.  Vortex tube operated panel coolers are mounted on the top of electrical and electronic cabinets to send clean, cool air down into the panel, displacing hot air around sensitive electronics.  The vortex electrical panel cooler is made of stainless steel to protect against rain, snow, humidity, outdoor use, and corrosive environments. They work best in extremely hot and hazardous environments.   Vortex tubes themselves can be made of aluminum, brass or stainless steel.  However,l Nex Flow® chooses to use stainless steel for longer life and durability in all factory environments.

There are three standard sizes for Nex Flow®  Frigid-X® Vortex tubes:

• Small: 2, 4, or 8 SCFM
• Medium: 10, 15, 26, 30, and 40 SFM
• Large: 10 000 BTU/hour and is used for heavy industrial uses

The tube comes assembled with a brass generator, which provides a longer lifespan in high temperature environments compared to plastic used by some manufacturers.  Continuous operation of the Vortex tube compressed air panel cooler is best when constant cooling and/or a positive purge of waste/heat is required.

NOTE: The cooling effect (BTU/hr) is determined by flow and temperature drop.  

All Vortex tubes have a generator which is sized for a certain flow.  There are two basic types of generators – one to produce extreme cold temperatures (maximum cold temperature out called the C generator) and another type to produce maximum amount of cooling (maximum refrigeration called the H generator). The Vortex Tube takes compressed air and converts it to cold air as low as minus 50° F (minus 46° C) at one end and hot air at the other up to 260° F (127° C).

If cooling effect is important to the manufacturing application, then the cold air flowing out of the Vortex tube should be between 60% – 80%.  This is called the Cold Fraction. Most industrial applications require the 60% to 80% setting and the H generator for optimal cooling.  The Vortex Tubes with a C generator limits the Cold Fraction to a low value which produces extremely cold temperatures if required.

When the internal temperature of an enclosure reaches the desired temperature, it is useful to have an automatic on-off thermostat to save energy costs.

How does cold and hot air come from ONE compressed-air stream?

A fluid, such as water or air that rotates around an axis — like a tornado — is called a vortex. A Vortex Tube turns factory compressed air into two airstreams, one very cold and one hot, using no moving parts.  It creates a tornado or vortex of compressed air that separates the fluid into two air streams: one hot and one cold. Vortex generator, which is a stationary and interchangeable part, regulates the volume of compressed air. The generator alters the airflows and temperature ranges.

The rotating air is forced down the inner walls of the hot tube at speeds reaching 1,000,000 rpm. At the Hot end of the tube, a small portion of this air exits through a hot air exhaust. The remaining air is forced back inside itself in the reverse direction through the center of the incoming air stream to create a stream of cold air at the cold end. The outside stream of air becomes hot and exhausts at the hot end of the tube. The heat of the slower-moving air directed at the cold end is shifted to the fast-moving incoming air, creating super-cooled air. The colder air flows through the center of the generator and exits through the cold air exhaust.

Different experimental methodologies have been used to confirm the flow behaviour inside a Vortex Tube and addresses the mechanism for the generation of cold and hot streams. “Energy analysis of flow properties in an air-operated Vortex Tube indicates that there is no outward energy transfer in the hot region of the Vortex Tube. The governing factor to determine temperature is attributed to the stagnation and mixture of flow structure.”

NOTE: The Vortex temperatures and capacities can vary by adjusting the hot end plug at the hot end of the tube and by using different generators.

The good news is that Vortex Tube behaviour is predictable and controllable. The Vortex Tubes have an adjustable valve at the hot end which controls the volume of the air flow and the temperature exiting at the cold end. By adjusting the valve, you control the “cold fraction”, which is the percentage of total input compressed air that exits the cold end of the Vortex Tube.  Nex Flow’s Vortex Tubes may also be supplied with a fixed pre-set “cold fraction” instead of an adjustable valve.

The recommended guideline is: the less cold air released, the colder the air will become. The control knob adjusts the cold fraction, which is also a function of the type of vortex generator that is in the tube. There could be a high (industrial applications) or low cold fraction generator. 

A high cold fraction tube can result in 50-90°F (28-50°C) below the compressed air temperature. They also have greater air flow, yet they do not give the lowest possible temperatures. The maximum refrigeration capacity (greatest BTU/H or Kcal/H) results from a combination of airflow and cold temperature.  A low cold fraction tube releases a smaller volume of air but extremely cold temperatures (down to -40°F/-40°C). Therefore, colder air is released with less volume.  In summary, the maximum refrigeration (BTU/H or Kcal/H) capacity occurs with a higher cold fraction tube. 

The hot air is vented to the atmosphere above the Vortex Tube through a muffler to reduce noise (optional). For Vortex Tube operated cabinet enclosure coolers (Panel Coolers),  cold air in the control panel or cabinet is vented below the Vortex Tube. The cold air enters the panel through the cold distribution hose. Holes are punched into the hose kit to deliver the cold air evenly inside the panel where required.  An optional muffler, in the cabinet, is added to reduce noise of exhausting air. Once sealed, the outside air is never allowed to enter the control panel.

How do you control the flow rate and temperature when using a Frigid-X® Vortex Tube?

The flow rate and temperature in a Vortex Tube are interdependent. To set the Vortex Tube to the desired temperature simply insert a thermometer at the cold end and adjust the hot end valve. The optimum cooling effect is achieved when the difference from the inlet air temperature and the cold air drops is 50oF (28 oC).

When using a Vortex tube in cooling laboratory samples or to test circuit boards, a ‘C’ generator is used because it limits the cold end flow rate to lower levels and produces very cold temperatures.

In summary, opening the adjustable hot end valve causes the cold air flow to decrease and the temperature drops. Closing the adjustable cold end valve increases the cold air flow and the temperature rises.

What are the advantages of the Vortex Tube compared to other cooling solutions?

Vortex Tubes have many advantages over other cooling solutions. They use no electricity and are safe since they have no explosive risk. They have no RF interference. They cool without refrigerants (CFCs/HCFCs) or moving parts for trouble free and reliable operation. Vortex Tubes are compact, lightweight, and easy to install especially in tight areas.

What is the Primary Application of Vortex Tubes?

The main function of a Vortex tube is to provide air conditioning for enclosures in an industrial environment. It provides cold, dry, and clean air to enclosures, which house sensitive instruments.

Nex Flow offers four types of “Packaged” Vortex Tubes:

Frigid-X® Adjustable Spot Cooler is a low cost and maintenance free system that comes with a magnetic base for mounting. This type of vortex tube is generally used in a laboratory environment where temperature adjustment is needed. the units are portable and easily mounted.

NOTE: If more cooling is the 30 SCFM (850 SLPM) generator is available for up to 2,100 Btu/hr. of cooling.

Frigid-X® Tool Cooler is designed for all types of dry machining applications for materials like plastic, glass, ceramic, titanium, and others such as aluminum (if not deep hole drilling), and it has been used for cooling needles in sewing and cutters for textile cutting. It can replace mist systems that are sometimes toxic when lubrication is not required. It is basically a no mess, no residue, and low-cost cooling solution. If some lubrication is required – a variation called Nex Flow® Sub-Zero Vortex® – can do just the job.

Frigid-X® Mini Spot Cooler  is designed to cool small parts and produces a stream of 15 to 20 oF (minus -9.5 to -7 oC) of cold air to prevent heat buildup depending on inlet air temperature. It is often used to improve heat tolerances in machining of small critical parts and increase production rates.

Frigid-X® Box Cooler/Panel Cooler – For cooling small enclosures in laboratories, special environmental chambers, and various other application where an enclosure needs to be cooled.

Accessories

The following is a list of Nex Flow accessories sold with the Frigid-X® cooler products:

• Hose Distribution kit to distribute the cold air inside the enclosure
• Cold end muffler (Optional): The Cold End Muffling Kit consists of a silencer and all necessary fittings to connect to the Panel Cooler at the cold air outlet inside the electrical control panel. Depending on the capacity of the specific Panel Cooler, the dBA reduction offered by the Cold End Muffling Kit is 5 to 6 dBA. It is easy to install. Depending on the installation space available, it can be installed with a vertical or horizontal silencer.
• Hot end muffler (Optional): The Hot End Muffling Kit consists of an ABS Plastic sleeve with silencing material fitted over the hot end of the Panel Cooler, outside of the control panel. The dBA reduction offered by the Hot End Muffling Kit is 2 dBA. It is also easy to install by fitting it over the top of the Panel Cooler. In addition to noise reduction, the hot end muffler offers additional protection from the hot end of the Panel Cooler.
• Optional side mount is available for installing in tight spaces: Two sizes are available – one for coolers 8 SCFM and under capacity; the other for larger coolers. The slim design minimizes the space of the cooler when mounted on the side.
• Solenoid valve
• Thermostat

NOTE: The Side Mount is attached on the side of a cabinet but as near the top as possible so that the Panel Cooler can fit into the limited space they have.  The hose distribution kit should be strung along the top of the inside of the panel with some holes to exhaust the cold air to avoid stratification of hot air at the top of the enclosure.  Properly installed, the Nex Flow® Frigid-X® Panel Cooler with Side Mount can provide maintenance free air conditioning for your electrical and electronic controls.

What types of Enclosures can be Used with a Vortex Tube?

The first step is solving over-heating internal panel heating issue is to identify the correct enclosure. Nex Flow Frigid-X® Panel Coolers are approved by Underwriters Laboratory (ULC Component Recognized). Nex Flow can be installed in four types of UL listed NEMA rated electrical panel coolers:

• NEMA Type 12 (IP 54) – This enclosure is for environments where no liquids (dripping or splashing) or corrosive material is present. Used for industrial use where the enclosure must keep dust away from electronics and protects equipment against ingress of solid foreign objects (falling dirt and circulating dust).
• NEMA 3R (IP 14) – A weatherproof enclosure that is sealed, has gasketed raised lids, and quick release lockable latches. Used to protect electrical panels outdoors. The strong enclosure will not be damaged if ice forms on the outside of the enclosure.  It protects equipment against the harmful effects on the equipment due to the ingress of water (rain, sleet, snow).
• Patented NEMA Type 4-4X (IP 66)—This patented designed watertight enclosure provides personal protection against hazardous parts. Used to protect outdoor equipment and is splash resistant. It protects instruments from water (rain, sleet, snow, splashing water, and hose directed water). If ice forms on the outside of the enclosure, no damage will be sustained by the equipment inside. This enclosure provides additional protection against corrosion.
• Patented NEMA Type 4-4X-316L (IP 66) –The 316L stainless steel sealed enclosure is oil-tight, spray resistant, and is used in wet environments. It provides protection against dust. Used in food service, pharmaceutical, and extremely corrosive environments where 303/304 stainless steel is not adequate.

FEATURED PRODUCTS

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How to install a Vortex Tube?

When spot cooling with a Vortex Tube, it is good to have a small flexible hose connection at the cold end to direct the cold air to the spot being cooled. You need to keep the hose length as short as possible, preferable under 8 inches. Watch how to install a Vortex Tube below!
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Appendix A: Advantages of using Vortex Tubes
Additional advantages of Vortex Tube usage includes:

• Metal generators, which are interchangeable
• Adjustable temperature range
• High precision engineered
• Smooth internal surface
• All stainless-steel body with welded connections
• No moving parts; maintenance free because driven by air not electricity
• Low cost solution
• Made of stainless-steel with a brass generator as a standard item; no cheap plastic
• The generators control the air consumption and are easily interchangeable.
• Quiet because of optional hot and cold mufflers available
• Extension of tool life reducing downtime and tooling costs.
• Portable: Strong magnet is useful for easy attachment to metal (Tool Cooling System)
• Keeps out moisture and dirt in enclosure cooling applications

Appendix B: What are the main issues with other cooling solutions for Panel Cooling?
Compressed air panel coolers are the best option because:

• Water cooled heat exchangers use water which is not compatible with electrics. In addition, scale buildup can cause reduced effectiveness over time and downtime for 4 descaling.
• Refrigerant CFC or HCFC Heat Exchangers are costlier with higher installation cost and lower life expectancy Installation requires a floor drain for condensate. Machine vibration can cause loss of refrigerant and component failure. Average replacement cost of a compressor can be High. Filters require monitoring and change to prevent 4 failures.

Appendix C: Additional Applications of Vortex Tubes
The following is a list of applications for the Vortex Tube:

• Cool CCTV Cameras
• Cool Machine operations/tooling
• Cool electronic and electrical controls
• Set hot melt adhesives
• Cool soldered parts
• Cool gas samples
• Cool heat seals
• Cool enclosures that house sensitive electronics and protect them from corrosive or dirty environments.
• Solder Cooling
• Adjusting thermostats
• Cool plastic machined parts
• Set hot melt adhesives
• Cool welding horns on ultrasonic
• Cool molded plastics
• Cool Electronic components
• Cool heat shrink tubing
• Improve dry machining applications
• Does not use coolant
• Cheaper solution
• Tool Cooling Systems are used for machining plastics, titanium, glass, and ceramics, testing sensors, setting adhesives,
  • Sharpening Tools
  • Routing
  • Machining Plastics
  • Drill and Cutter Grinding
  • Milling, Drilling, Routing and Surface Grinding
  • Plunge and Form Grinding
  • Setting Hot Melt Adhesives
  • Laser Cutting
  • Tire and Rubber Grinding
  • Band Saw Blade Cooling
  • Chill Roll Nip Cooling
• Mini Spot Cooler applications:
  • Solder Cooling
  • Adjusting thermostats
  • Cool plastic machined parts
  • Set hot melt adhesives
  • Cool welding horns on ultrasonic
  • Cool molded plastics
  • Cool Electronic components
  • Cool heat shrink tubing
• Humidity and temperature control: Ideal in typically very hot environments
• Keep the electrical panel clean
• Cooling an industrial camera using a Vortex tube
• Keep electronics free of condensation
• Programmable controllers
• System control cabinets
• Motor control centers
• Relay panels
• NC/CNC machine controls
• Computer panels
• Modular Control Centers
• Laser Housing Cooling
• Electronic scale cooling
• Modular control centers
• Food Service Equipment controls
• Computer and Server Labs
• Environments where cooler panels are near Personnel
• When noise reduction is required
• Programmable controllers
• Line Control cabinets
• Cool laser housings
• Electronic scales
• Small panel coolers are ideal for inkjet markers, recorders, and other small control panel applications
• Medium panel coolers can be installed on almost any other panel size and multiple units can be used on very large panels
• Used for cooling housing that has wired and wireless communications equipment

COMPRESSED AIR USED IN THE FOOD INDUSTRY

The food industry is huge worldwide.  In the USA alone, there are approximately 1,300 facilities employing about 112,000 people mainly for canning, freezing, and dehydrating fruits and vegetables. This segment represents approximately 7.5% of the dollar value of shipments of the entire U.S. food industry¹. In many fruit and vegetable processing plants, compressed air systems are used for air cleaning of containers prior to product filling, automated product sorting, and product packaging systems². (1,2 Eric Masanet and Ernst Worrell, Lawrence Berkeley National Laboratory, “The Energy Star for Industry Program”, Compressed Air Best Practices Magazine®, October 2006, page 14-15)

There are tens of thousands of facilities in other segments of the food industry using compressed air. Some, like bakeries, use this technology for blow-off applications. Other segments use them to clean containers before filling. Additionally, compressed air is also used to sort, cut, shape and convey food products.  

Another applications are in form, fill and seal operations for cartons. Because these machines must be cleaned thoroughly and regularly to maintain sanitary standards, through washed-down pneumatic systems are preferred since hydraulic systems can have oil leak issues.  Pneumatic also has much less downtime and maintenance needs than hydraulic systems.

Compressed air is very important in the food industry, both for food processing and in the packaging operations.  The air must be contaminant free to ensure food quality and protection. There are standards in all developed countries to have a maximum micron content in filtration and also for dew point control. Dew points of the air at line pressure must be under minus 15 degrees oF (-26 degrees oC) to inhibit growth of microorganisms and fungi.

Some filtration companies, therefore, specializes in filters that meet particular standards of filtration necessary for various processes within food production facilities.

It is not only particulate but also oil which can be a concern.  Where necessary, oil- free compressors are used to supply the compressed air.  

CONTACT – NON CONTACT APPLICATIONS

Compressed air must be purified of contaminants before use in the food industry. The contaminants are water vapor and moisture, solid particulates (including spores) and oil aerosols and vapors.   

Moisture can often be trapped in the piping system near the point-of-use in applications where compressed air comes into contact with food products. Microorganisms and fungus can grow inside the piping system and then be blown into food products or containers. Drying the air to a specified pressure dewpoint is the simple way to eliminate moisture in the system.  The dew point specification can vary from +37 oF (+3 oC) or -40 oF (-40 oC). In some facilities, both of these specifications may be used depending upon whether compressed air has any possibility of coming into contact with food products.

Contact application is when the compressed air is used as part of the production and processing including packaging and transportation of food production or if compressed air comes into direct contact with actual food products. If this is the case, the compressed air needs to be purified to a higher standard than for non-contact applications usually to the -40 oF (-40 oC) dew point, with oil free air and very fine filtration to keep out particulate.

One way to accomplish this is with desiccant (adsorption) type compressed air dryers located in the compressor room (centralized air treatment). Each facility can determine if further point-of-use air dryers (de-centralized treatment) are needed. Point-of-use air dryers may be of either desiccant (adsorption) or membrane-type technology.

Another way to purify the compressed air is by using coalescing filters will remove solid particulates and total oil (aerosol + vapor). Activated carbon filters are usually required as well to remove oil vapors. As with the air dryers, de-centralized filtration may be needed in addition to the centralized filtration system.

Food plants are ideal applications for the use of engineered nozzles and air knives. These are used to blow off on a product and in packaging applications.  These accessories conserve compressed air consumption by utilizing the Coanda effect to entrain surrounding atmospheric air along with the compressed air and create a high velocity, high flow, and a high energy stream of air.


Some applications includes:
– Blow off water after washing a product prior to packaging
– Blow off excess sugar from muffins prior to oven to avoid burnt product
– Cool a product prior to packaging to increase line speed and shorten conveyor length

This air “amplifying” technology not only reduces compressed air energy consumption it also reduces noise levels and have a dead end pressure under 30 PSIG to meet OSHA safety standards on open compressed air exhaust contact.

Non-Contact applications can be categorized into high risk or low risk.  This is when the compressed air is exhausted into the local atmosphere of the food preparation, production, processing, packaging or storage.   

Example of a high risk application is where compressed air is used in a blow-molding process to create a package –then product is put into the package at a later time. Many food processors have their own in-house production lines to create their own packaging.  If there is a delay in the use of the packaging, oil, moisture, and particulates (notably bacteria) could be present if the compressed air is not pure enough. Hence the higher standard for cleanliness. 

In low risk applications higher dew point may be acceptable using a centralized refrigerated type compressed air dryer. Additional point-of-use air dryers (de-centralized) may still be required.  Significant portions (often over 50%) of compressed air in a facility will have absolutely no contact with food products or food-packaging machinery. In this case less costly methods for air treatment are acceptable.  Refrigerated type compressed air dryers normally have significantly lower energy costs than desiccant air dryers. Coalescing filters are required to remove solid particulates and total oil (aerosol + vapor) to the same specification levels as in contact applications and activated carbon filters will be required as well to remove oil vapors. As with the air dryers, each facility can determine if de-centralized filtration is required in addition to centralized filtration.

FEATURED PRODUCTS

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How does the Venturi System Work?

A Venturi System reduces pressure when a fluid flows through a constricted section (or choke) of a pipe. In 1797, Giovanni Battista Venturi performed experiments on flow in a cone-shaped tube and built the first flowmeter for closed pipes called the “Venturi tube”.  A Venturi vacuum is created by a pump with compressed air running through it, yet the pump has no moving parts. Compressed air runs through the initial chamber, then a smaller portal that opens into another larger chamber, which is like the first one.

The static pressure in the first measuring tube (1) is higher than at the second (2), and the fluid speed at “1” is lower than at “2”, because the cross-sectional area at “1” is greater than at “2”.https://en.wikipedia.org/wiki/Venturi_effect

Constricting a pipe where fluid flows through results in lower pressure. This principle is counter intuitive to common sense. Why does the pressure decrease? Where does the fluid go if the pathway is constricted? When fluid starts to flow, its velocity around the orifice in the pipe increases significantly because of the restriction in the cross-section. An illustration of this is water flowing through a pipe. Water is a liquid that is not easily compressed. When the water flows through the constricted region of a pipe, the water flows faster.  The same volume of water must pass through the same space quicker. The smaller the constricted region of the pipe is compared to the original radius, the faster the speed of the fluid.

The faster the moving fluid, the lower the pressure (i.e. Bernoulie’s principle) and the higher the velocity, the greater the difference in differential pressure measured. Abrupt restrictions generate severe turbulence in a fluid. Adding a nozzle that are suited for higher flow velocities to fluids with abrasive particles will reduce turbulence and creates less pressure loss.  Turbulence reduction is greater with Venturi nozzles and tubes where the restriction is created by longer, conical constrictions in the pipe wall.

NOTE: The longer the exhaust section of the pipe, the stronger the vacuum effect.

All Venturi systems, including gauges, meters, nozzles, orifice plates, chokes, and pipes can be supplied with different restriction diameter sizes so that the pressure loss and differential pressure generated can be optimized for the process conditions and applications. “In fluid dynamics, an incompressible fluid’s velocity must increase as it passes through a constriction in accord with the principle of mass continuity, while its static pressure must decrease in accord with the principle of conservation of mechanical energy” (Wikipedia, Venturi effect, Retrieved on September 18, 2018).  Therefore, any gain in fluid kinetic energy and velocity as it flows through a restriction is balanced by a drop-in pressure.

Interesting note:  The mass flow rate for a compressible fluid will increase with increased upstream pressure, which will increase the density of the fluid through the constriction (though the velocity will remain constant). This is the principle of operation of a de Laval nozzle. Increasing source temperature will also increase the local sonic velocity, thus allowing for increased mass flow rate but only if the nozzle area is also increased to compensate for the resulting decrease in density.

The Venturi system consists of:

• Venturi Vacuum Switch or Nex Flow Ring Vac®
• Hose or pipe
• Minimum 2.5 CFM @ 90 PSI

The Venturi system increases the sucking capacity of any air compressor. To configure a Venturi Vacuum, plug the compressor into one end, move the switch to the vacuum setting, and plug the other end into a vacuum device.

The main component is a Venturi tube. As fluid flows through a length of pipe of changing diameter. To avoid undue aerodynamic drag, a Venturi tube typically has an entry cone of 30 degrees and an exit cone of 5 degrees. (Wikipedia, Retrieved September 18, 2018).

Accessories

• Quick disconnect/connect nozzle fitting
• Pressure or vacuum gauges to monitor how much vacuum is created with the system
• Vacuum pump to collect material and then use the Venturi system to move the material a greater distance

Advantages of a Venturi Vacuum System

The best advantages of a Venturi Vacuum System is that it:

• Creates a high vacuum and amplified flow to generate a strong conveying force to move any material with ease.
• Reduces energy costs with less air consumption and uses less pressure.
• Less likely to contaminate air flow because of the straight through design, which prevents clogging.
• Lightweight and portable; Simple configuration, which is easier to manufacture and less expensive to purchase.  Quickly and easily assembled and attaches to existing configuration. Has no valves and requires no filters.
• Configurable: Standard, Threaded (NPT or BSP) or Flanged connection
• Available in a wide choice of materials: Anodized/hard anodized Aluminum, 304/316L stainless steel,  and Teflon. Built to last: materials are treated to ensure longevity in the product’s life cycle
• Exceeds multi-stage pumps by 2 to7 times
• No electrical or explosion hazard

Venturi System Applications

Venturi tubes are used in processes where permanent pressure loss is not tolerable and where maximum accuracy is needed in case of highly viscous liquids. It is also used in applications where they replace electrically powered vacuum pumps:

• Gas venting
• Moving metal parts in a machinery rough environment:
  • Hopper loading; Plastic pellets for injection molding
  • Trim Removal
  • Filling operations
  • Material Transfer
  • Sandblasting
• Gas through a transmission line or scrubber: Moves wet and dry material or fluid through a pipe
• Energy Transmission: Transporting solvents and chemicals, for example, oil and gas, steam
• Convert a standard air compressor into a suction machine to secure products with a uniform suction to secure a base to a surface. Using an air compressor as a clamping force also prevents the need for holes on a work surface.
• Measure the speed of a fluid, by measuring pressure changes at different segments of the device:
  • Measure fuel or combustion pressures in jet or rocket engines
  • Measure small and large flows of water and wastewater
• In metrology (science of measurement) for gauges calibrated for differential pressures.
• Water aspirators that produce a partial vacuum using the kinetic energy from the faucet water pressure
• Connect your vacuum bag to make vacu-formed laminates
• Vacuum forming operations for efficient industrial applications
• Atomizers that disperse perfume or spray paint (i.e. from a spray gun).

FEATURED PRODUCTS

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What is a Vacuum Pump?

A vacuum pump is a device, which was invented in 1650 by Otto von Guericke. It removes air and gas molecules from a sealed or confined space, which results in a partial vacuum. Sometimes vacuum pumps remove gas from an area, leaving a partial vacuum behind or remove water from one area to another, such as a sump pump does in a basement.  

The performance of a vacuum pump is measured on the speed of the pump or the volume of flow at the inlet in volume per unit of time. The pumping rate fluctuates for each type of pump and the gas/liquid/fluid that it is used on. The number of molecules pumped out of the container per unit of time or throughput is another performance factor.